6k61

Cryo-EM structure of the tetrameric photosystem I from a heterocyst-forming cyanobacterium Anabaena sp. PCC7120

Method: ELECTRON MICROSCOPY

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1. Protein Identity and Related Structures Protein Identity & Related Structures

Photosystem I P700 chlorophyll a apoprotein A1

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XI × 2 （P58577） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAA_NOSS1
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–752； UniProt 1–752 Author chain a； PDBConstruct 1–752； UniProt 1–752

Photosystem I 4.8 kDa protein

OrganismNot specified

UniProt P58566

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XI × 2 （P58577） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAX_NOSS1
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain X； PDBConstruct 1–44； UniProt 1–44 Author chain x； PDBConstruct 1–44； UniProt 1–44

Photosystem I P700 chlorophyll a apoprotein A2 1

OrganismNot specified

UniProt P58565

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XI × 2 （P58577） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAB1_NOSS1
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain B； PDBConstruct 1–741； UniProt 1–741 Author chain b； PDBConstruct 1–741； UniProt 1–741

Photosystem I iron-sulfur center

OrganismNot specified

UniProt P0A410

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XI × 2 （P58577） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAC_NOSS1
Isoform	—
PDB entities	4
Chains and sequence ranges	Author chain C； PDBConstruct 1–81； UniProt 1–81 Author chain c； PDBConstruct 1–81； UniProt 1–81

Photosystem I reaction center subunit II

OrganismNot specified

UniProt P58573

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XI × 2 （P58577） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAD_NOSS1
Isoform	—
PDB entities	5
Chains and sequence ranges	Author chain D； PDBConstruct 1–139； UniProt 1–139 Author chain d； PDBConstruct 1–139； UniProt 1–139

Photosystem I reaction center subunit IV

OrganismNot specified

UniProt P58575

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XI × 2 （P58577） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAE_NOSS1
Isoform	—
PDB entities	6
Chains and sequence ranges	Author chain E； PDBConstruct 1–70； UniProt 1–70 Author chain e； PDBConstruct 1–70； UniProt 1–70

Photosystem I reaction center subunit III

OrganismNot specified

UniProt P58564

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XI × 2 （P58577） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAF_NOSS1
Isoform	—
PDB entities	7
Chains and sequence ranges	Author chain F； PDBConstruct 1–164； UniProt 1–164 Author chain f； PDBConstruct 1–164； UniProt 1–164

Photosystem I reaction center subunit IX

OrganismNot specified

UniProt P58568

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XI × 2 （P58577） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAJ_NOSS1
Isoform	—
PDB entities	8
Chains and sequence ranges	Author chain J； PDBConstruct 1–49； UniProt 1–49 Author chain j； PDBConstruct 1–49； UniProt 1–49

Photosystem I reaction center subunit PsaK 1

OrganismNot specified

UniProt P58583

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XI × 2 （P58577） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAK1_NOSS1
Isoform	—
PDB entities	9
Chains and sequence ranges	Author chain K； PDBConstruct 1–86； UniProt 1–86 Author chain k； PDBConstruct 1–86； UniProt 1–86

Photosystem I reaction center subunit VIII

OrganismNot specified

UniProt P58560

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit XI × 2 （P58577） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAI_NOSS1
Isoform	—
PDB entities	10
Chains and sequence ranges	Author chain I； PDBConstruct 1–46； UniProt 1–46 Author chain i； PDBConstruct 1–46； UniProt 1–46

Photosystem I reaction center subunit XI

OrganismNot specified

UniProt P58577

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XII × 2 （Q8YNB0） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAL_NOSS1
Isoform	—
PDB entities	11
Chains and sequence ranges	Author chain L； PDBConstruct 1–172； UniProt 1–172 Author chain l； PDBConstruct 1–172； UniProt 1–172

Photosystem I reaction center subunit XII

OrganismNot specified

UniProt Q8YNB0

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 24	Photosystem I P700 chlorophyll a apoprotein A1 × 2 （P58576） Photosystem I 4.8 kDa protein × 2 （P58566） Photosystem I P700 chlorophyll a apoprotein A2 1 × 2 （P58565） Photosystem I iron-sulfur center × 2 （P0A410） Photosystem I reaction center subunit II × 2 （P58573） Photosystem I reaction center subunit IV × 2 （P58575） Photosystem I reaction center subunit III × 2 （P58564） Photosystem I reaction center subunit IX × 2 （P58568） Photosystem I reaction center subunit PsaK 1 × 2 （P58583） Photosystem I reaction center subunit VIII × 2 （P58560） Photosystem I reaction center subunit XI × 2 （P58577） CHLOROPHYLL A ISOMER × 2 CHLOROPHYLL A × 188 PHYLLOQUINONE × 4 IRON/SULFUR CLUSTER × 6 BETA-CAROTENE × 46 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 6 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSAM_NOSS1
Isoform	—
PDB entities	12
Chains and sequence ranges	Author chain M； PDBConstruct 1–32； UniProt 1–32 Author chain m； PDBConstruct 1–32； UniProt 1–32

The page prioritizes protein identity, the current assembly, associated components, oligomeric state and cross-PDB links. Chain mapping and sequence ranges are retained as data evidence. Internal IDs, import timestamps and assembly operation expressions are maintenance fields and are not shown here.

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2. Structure Basics 2. Structure Basics

Entry ID entry_id	6k61
Deposition date deposition_date	2019-05-31
Structure title title	Cryo-EM structure of the tetrameric photosystem I from a heterocyst-forming cyanobacterium Anabaena sp. PCC7120
Keywords keywords	Photosystem I, PSI, PCC7120, PHOTOSYNTHESIS; PHOTOSYNTHESIS
Experimental Method method	ELECTRON MICROSCOPY

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3. Official assembly/model SAXS Official SAXS Profiles

This page reads only the latest assembly calculations. Every curve maps to an explicit PDB entry, official biological assembly and coordinate model.

6k61__assembly_1__model_1

Assembly 1 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

6k61__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

6k61__assembly_1__model_1 | P(r) · Pending

P(r) will be calculated and displayed separately for the same assembly/model.

Rg（Guinier）	63.78 Å
Rg (electron density)	63.69 Å
Total Rg	63.66 Å
Atom count	49283
Residues	4542
Excluded volume	922010 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`6k61__assembly_1__model_1`	24-meric （24）	Success	4.1.3-1-20251215 (887e7ef)	View Download

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4. Crystallography and Experiment 4. Crystallography & Experiment

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5. Entities and Polymers Entities & Polymers (20)

Entity 1 Entity 1 polymer

Description description	Photosystem I P700 chlorophyll a apoprotein A1
Molecular weight formula_weight	83289.7 kDa
EC 编号 ec_number	1.97.1.12
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,a
Atom count atom_count	49283

MTISPPEREEKKARVIVDKDPVPTSFEKWAQPGHFDRTLARGPKTTTWIWNLHALAHDFDTHTSDLEDISRKIFAAHFGHLAVVTIWLSGMIFHGAKFSNYEAWLSDPLNVRPSAQVVWPIVGQDILNGDVGGGFHGIQITSGLFQVWRGWGITNSFQLYCTAIGGLVLAGLFLFAGWFHYHKRAPKLEWFQNVESMLNHHLQVLLGCGSLGWAGHLIHVSAPINKLMDAGVAVKDIPLPHEFILNKSLLIDLFPGFAAGLTPFFTLNWGQYADFLTFKGGLNPVTGGLWMTDIAHHHLAIAVVFIIAGHQYRTNWGIGHSIKEILENHKGPFTGEGHKGLYENLTTSWHAQLATNLAFLGSLTIIIAHHMYAMPPYPYLATDYATQLCIFTHHIWIGGFLIVGGAAHAAIFMVRDYDPVVNQNNVLDRVIRHRDAIISHLNWVCIFLGFHSFGLYIHNDTMRALGRPQDMFSDTAIQLQPVFAQWVQNLHTLAPGGTAPNALEPVSYAFGGGVLAVGGKVAMMPIALGTADFLIHHIHAFTIHVTVLILLKGVLFARSSRLIPDKANLGFRFPCDGPGRGGTCQVSGWDHVFLGLFWMYNSLSIVIFHFSWKMQSDVWGTVDAAGNVSHITGGNFAQSAITINGWLRDFLWAQASQVINSYGSALSAYGLMFLGAHFVWAFSLMFLFSGRGYWQELIESIVWAHNKLKVAPAIQPRALSITQGRAVGVAHYLLGGIATTWAFFHAHILSVG

Entity 2 Entity 2 polymer

Description description	Photosystem I 4.8 kDa protein
Molecular weight formula_weight	4872.8 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	X,x

MAKAKISPVANTGAKPPYTFRTGWALLLLAVNFLVAAYYFHIIQ

Entity 3 Entity 3 polymer

Description description	Photosystem I P700 chlorophyll a apoprotein A2 1
Molecular weight formula_weight	83457.0 kDa
EC 编号 ec_number	1.97.1.12
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B,b

MATKFPKFSQDLAQDPTTRRIWYAMAMGNDFESHDGMTEENLYQKIFATHFGHLAIIFLWASSLLFHVAWQGNFEQWIKDPLHVRPIAHAIWDPHFGKPAIEAFTQAGANGPVNIAYSGVYHWWYTIGMRTNTELYTGSVFLLLFASLFLFAGWLHLQPKFRPSLAWFKSAESRLNHHLAGLFGVSSLAWAGHLIHVAIPESRGQHVGWDNFLSTAPHPAGLQPFFTGNWGVYAQNPDTAGHIFSTSQGAGTAILTFLGGFHPQTESLWLTDMAHHHLAIAVLFIVAGHMYRTNFGIGHSIKEMMNAKTFFGKPVEGPFNMPHQGIYDTYNNSLHFQLGWHLACLGVVTSWVAQHMYSLPSYAFIAKDYTTQAALYTHHQYIAIFLMVGAFAHGAIFLVRDYDPEQNKGNVLERVLQHKEAIISHLSWVSLFLGFHTLGLYVHNDVVVAFGTPEKQILIEPVFAQFIQAAHGKVLYGLDTLLSNPDSVAYTAYPNYANVWLPGWLDAINSGTNSLFLTIGPGDFLVHHAIALGLHTTTLILVKGALDARGSKLMPDKKDFGYAFPCDGPGRGGTCDISAWDSFYLSLFWALNTVGWVTFYWHWKHLGIWQGNVAQFNENSTYLMGWFRDYLWANSAQLINGYNPYGVNNLSVWAWMFLFGHLVWATGFMFLISWRGYWQELIETLVWAHERTPIANLVRWKDKPVALSIVQARVVGLAHFTVGYVLTYAAFLIASTAGKFG

Entity 4 Entity 4 polymer

Description description	Photosystem I iron-sulfur center
Molecular weight formula_weight	8825.2 kDa
EC 编号 ec_number	1.97.1.12
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	C,c

MSHTVKIYDTCIGCTQCVRACPTDVLEMVPWDGCKAAQVASSPRTEDCVGCKRCETACPTDFLSIRVYLGAETTRSMGLAY

Entity 5 Entity 5 polymer

Description description	Photosystem I reaction center subunit II
Molecular weight formula_weight	15176.2 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	D,d

MAETLSGKTPLFAGSTGGLLTKAVEEEKYAITWTSPKAQVFELPTGGAATMHEGENLLYIARKEYGIALGGQLRKFKITNYKIYRILPSGETTFIHPADGVFPEKVNAGREKVRFNARSIGENPNPSQVKFSGKATYDA

Entity 6 Entity 6 polymer

Description description	Photosystem I reaction center subunit IV
Molecular weight formula_weight	7897.1 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	E,e

MVQRGSKVRILRPESYWFQDVGTVASVDQSGIKYPVIVRFDKVNYAGINTNNFAVDELIEVEAPKAKAKK

Entity 7 Entity 7 polymer

Description description	Photosystem I reaction center subunit III
Molecular weight formula_weight	17850.6 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	F,f

MRRLFALILVICLSFSFAPPAKALGADLTPCAENPAFQALAKNARNTTADPQSGQKRFERYSQALCGPEGYPHLIVDGRLDRAGDFLIPSILFLYIAGWIGWVGRAYLQAIKKDSDTEQKEIQLDLGIALPIIATGFAWPAAAVKELLSGELTAKDSEITVSPR

Entity 8 Entity 8 polymer

Description description	Photosystem I reaction center subunit IX
Molecular weight formula_weight	5499.4 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	J,j

MADKADQSSYLIKFISTAPVAATIWLTITAGILIEFNRFFPDLLFHPLP

Entity 9 Entity 9 polymer

Description description	Photosystem I reaction center subunit PsaK 1
Molecular weight formula_weight	8852.5 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	K,k

MLTSTLLAAATTPLEWSPTVGIIMVIANVIAITFGRQTIKYPSAEPALPSAKFFGGFGAPALLATTAFGHILGVGLVLGLHNLGRI

Entity 10 Entity 10 polymer

Description description	Photosystem I reaction center subunit VIII
Molecular weight formula_weight	5066.9 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	I,i

MATAFLPSILADASFLSSIFVPVIGWVVPIATFSFLFLYIEREDVA

Entity 11 Entity 11 polymer

Description description	Photosystem I reaction center subunit XI
Molecular weight formula_weight	18130.7 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	L,l

MAQAVDASKNLPSDPRNREVVFPAGRDPQWGNLETPVNASPLVKWFINNLPAYRPGLTPFRRGLEVGMAHGYFLFGPFAKLGPLRDAANANLAGLLGAIGLVVLFTLALSLYANSNPPTALASVTVPNPPDAFQSKEGWNNFASAFLIGGIGGAVVAYFLTSNLALIQGLVG

Entity 12 Entity 12 polymer

Description description	Photosystem I reaction center subunit XII
Molecular weight formula_weight	3538.2 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	M,m

MSSISDTQVYIALVVALIPGLLAWRLATELYK

Entity 13 Entity 13 non-polymer

Description description	CHLOROPHYLL A ISOMER
Molecular weight formula_weight	893.5 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 14 Entity 14 non-polymer

Description description	CHLOROPHYLL A
Molecular weight formula_weight	893.5 kDa
Source method src_method	syn
Copy count entity_count	188

Entity 15 Entity 15 non-polymer

Description description	PHYLLOQUINONE
Molecular weight formula_weight	450.7 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 16 Entity 16 non-polymer

Description description	IRON/SULFUR CLUSTER
Molecular weight formula_weight	351.6 kDa
Source method src_method	syn
Copy count entity_count	6

Entity 17 Entity 17 non-polymer

Description description	BETA-CAROTENE
Molecular weight formula_weight	536.9 kDa
Source method src_method	syn
Copy count entity_count	46

Entity 18 Entity 18 non-polymer

Description description	1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE
Molecular weight formula_weight	723.0 kDa
Source method src_method	syn
Copy count entity_count	6

Entity 19 Entity 19 non-polymer

Description description	1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL
Molecular weight formula_weight	795.1 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 20 Entity 20 non-polymer

Description description	1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE
Molecular weight formula_weight	787.2 kDa
Source method src_method	syn
Copy count entity_count	3

▼

6. Fold Classification (SCOP + CATH) 23 domains

SCOP 2.08 (9 domains)

Domain ID domain_id	d6k61a_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.29 — Photosystem I subunits PsaA/PsaB
Superfamily Superfamily superfamily	f.29.1 — Photosystem I subunits PsaA/PsaB
Family Family family	f.29.1.1 — Photosystem I subunits PsaA/PsaB

Domain ID domain_id	d6k61b_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.29 — Photosystem I subunits PsaA/PsaB
Superfamily Superfamily superfamily	f.29.1 — Photosystem I subunits PsaA/PsaB
Family Family family	f.29.1.1 — Photosystem I subunits PsaA/PsaB

Domain ID domain_id	d6k61c_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.58 — Ferredoxin-like
Superfamily Superfamily superfamily	d.58.1 — 4Fe-4S ferredoxins
Family Family family	d.58.1.2 — 7-Fe ferredoxin

Domain ID domain_id	d6k61d_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.187 — Photosystem I subunit PsaD
Superfamily Superfamily superfamily	d.187.1 — Photosystem I subunit PsaD
Family Family family	d.187.1.1 — Photosystem I subunit PsaD

Domain ID domain_id	d6k61e_
Class class	b — All beta proteins
Fold Fold fold	b.34 — SH3-like barrel
Superfamily Superfamily superfamily	b.34.4 — Electron transport accessory proteins
Family Family family	b.34.4.2 — Photosystem I accessory protein E (PsaE)

Domain ID domain_id	d6k61f_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.23 — Single transmembrane helix
Superfamily Superfamily superfamily	f.23.16 — Subunit III of photosystem I reaction centre, PsaF
Family Family family	f.23.16.1 — Subunit III of photosystem I reaction centre, PsaF

Domain ID domain_id	d6k61j_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.23 — Single transmembrane helix
Superfamily Superfamily superfamily	f.23.18 — Subunit IX of photosystem I reaction centre, PsaJ
Family Family family	f.23.18.1 — Subunit IX of photosystem I reaction centre, PsaJ

Domain ID domain_id	d6k61l_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.31 — Photosystem I reaction center subunit XI, PsaL
Superfamily Superfamily superfamily	f.31.1 — Photosystem I reaction center subunit XI, PsaL
Family Family family	f.31.1.0 — automated matches

Domain ID domain_id	d6k61m_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.23 — Single transmembrane helix
Superfamily Superfamily superfamily	f.23.19 — Subunit XII of photosystem I reaction centre, PsaM
Family Family family	f.23.19.1 — Subunit XII of photosystem I reaction centre, PsaM

CATH v4.4 (14 domains)

Domain ID domain_id	6k61A00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	1130 — Photosystem I p700 chlorophyll A apoprotein A1
Homologous superfamily homologous superfamily	10 — Photosystem I PsaA/PsaB

Domain ID domain_id	6k61B00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	1130 — Photosystem I p700 chlorophyll A apoprotein A1
Homologous superfamily homologous superfamily	10 — Photosystem I PsaA/PsaB

Domain ID domain_id	6k61C00
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	20 —

Domain ID domain_id	6k61D00
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1470 — Photosystem 1 Reaction Centre Subunit Ii; Chain: D;
Homologous superfamily homologous superfamily	10 — Photosystem I PsaD, reaction center subunit II

Domain ID domain_id	6k61E00
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	30 — SH3 type barrels.
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	6k61F00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	8 — Helicase, Ruva Protein; domain 3
Homologous superfamily homologous superfamily	110 — Photosystem I, reaction centre, subunit PsaF

Domain ID domain_id	6k61J00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	510 — Single helix bin

Domain ID domain_id	6k61a00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	1130 — Photosystem I p700 chlorophyll A apoprotein A1
Homologous superfamily homologous superfamily	10 — Photosystem I PsaA/PsaB

Domain ID domain_id	6k61b00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	1130 — Photosystem I p700 chlorophyll A apoprotein A1
Homologous superfamily homologous superfamily	10 — Photosystem I PsaA/PsaB

Domain ID domain_id	6k61c00
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	20 —

Domain ID domain_id	6k61d00
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1470 — Photosystem 1 Reaction Centre Subunit Ii; Chain: D;
Homologous superfamily homologous superfamily	10 — Photosystem I PsaD, reaction center subunit II

Domain ID domain_id	6k61e00
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	30 — SH3 type barrels.
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	6k61f00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	8 — Helicase, Ruva Protein; domain 3
Homologous superfamily homologous superfamily	110 — Photosystem I, reaction centre, subunit PsaF

Domain ID domain_id	6k61j00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	510 — Single helix bin

▶

Resolution resolution	2.37 Å
Resolution测定Method resolution_method	—
颗粒数 num_particles	71600

Cryo-EM structure of the tetrameric photosystem I from a heterocyst-forming cyanobacterium Anabaena sp. PCC7120

1. Protein Identity and Related Structures Protein Identity & Related Structures

Photosystem I P700 chlorophyll a apoprotein A1

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Photosystem I 4.8 kDa protein

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Photosystem I P700 chlorophyll a apoprotein A2 1

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Photosystem I iron-sulfur center

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Photosystem I reaction center subunit II

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Photosystem I reaction center subunit IV

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Photosystem I reaction center subunit III

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Photosystem I reaction center subunit IX

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Photosystem I reaction center subunit PsaK 1

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Photosystem I reaction center subunit VIII

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer