4kt0

Crystal structure of a virus like photosystem I from the cyanobacterium Synechocystis PCC 6803

Method: X-RAY DIFFRACTION

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

Photosystem I P700 chlorophyll a apoprotein A1

Synechocystis sp. PCC 6803

UniProt L8AHT3

State in the Current Structure

Assembly Physical composition Protein state Molecular copy count Associated components Data consistency
1 Protein heterocomplex Heteromer Protein 9 Photosystem I P700 chlorophyll a apoprotein A2 × 1 (L8AIC0) Photosystem I iron-sulfur center × 1 (L8AST2) Photosystem I subunit II × 1 (L8AFM8) Photosystem I reaction center subunit IV × 1 (L8ASH8) Photosystem I subunit III × 1 (L8AII8) Photosystem I reaction center subunit IX × 1 (L8AGL9) Photosystem I reaction center subunit PsaK × 1 (L8APJ0) Photosystem I reaction center subunit XII × 1 (L8ADF9) PHYLLOQUINONE × 2 IRON/SULFUR CLUSTER × 3 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 4 CHLOROPHYLL A ISOMER × 2 BETA-CAROTENE × 17 CHLOROPHYLL A × 90 DODECYL-ALPHA-D-MALTOSIDE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 1 CHLORIDE ION × 1 water × 4 Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence
UniProt name L8AHT3_9SYNC
Isoform
PDB entities 1
Chains and sequence ranges Author chain A; PDBConstruct 1–751; UniProt 1–751

Photosystem I P700 chlorophyll a apoprotein A2

Synechocystis sp. PCC 6803

UniProt L8AIC0

State in the Current Structure

Assembly Physical composition Protein state Molecular copy count Associated components Data consistency
1 Protein heterocomplex Heteromer Protein 9 Photosystem I P700 chlorophyll a apoprotein A1 × 1 (L8AHT3) Photosystem I iron-sulfur center × 1 (L8AST2) Photosystem I subunit II × 1 (L8AFM8) Photosystem I reaction center subunit IV × 1 (L8ASH8) Photosystem I subunit III × 1 (L8AII8) Photosystem I reaction center subunit IX × 1 (L8AGL9) Photosystem I reaction center subunit PsaK × 1 (L8APJ0) Photosystem I reaction center subunit XII × 1 (L8ADF9) PHYLLOQUINONE × 2 IRON/SULFUR CLUSTER × 3 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 4 CHLOROPHYLL A ISOMER × 2 BETA-CAROTENE × 17 CHLOROPHYLL A × 90 DODECYL-ALPHA-D-MALTOSIDE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 1 CHLORIDE ION × 1 water × 4 Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence
UniProt name L8AIC0_9SYNC
Isoform
PDB entities 2
Chains and sequence ranges Author chain B; PDBConstruct 1–731; UniProt 1–731

Photosystem I iron-sulfur center

Synechocystis sp. PCC 6803

UniProt L8AST2

State in the Current Structure

Assembly Physical composition Protein state Molecular copy count Associated components Data consistency
1 Protein heterocomplex Heteromer Protein 9 Photosystem I P700 chlorophyll a apoprotein A1 × 1 (L8AHT3) Photosystem I P700 chlorophyll a apoprotein A2 × 1 (L8AIC0) Photosystem I subunit II × 1 (L8AFM8) Photosystem I reaction center subunit IV × 1 (L8ASH8) Photosystem I subunit III × 1 (L8AII8) Photosystem I reaction center subunit IX × 1 (L8AGL9) Photosystem I reaction center subunit PsaK × 1 (L8APJ0) Photosystem I reaction center subunit XII × 1 (L8ADF9) PHYLLOQUINONE × 2 IRON/SULFUR CLUSTER × 3 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 4 CHLOROPHYLL A ISOMER × 2 BETA-CAROTENE × 17 CHLOROPHYLL A × 90 DODECYL-ALPHA-D-MALTOSIDE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 1 CHLORIDE ION × 1 water × 4 Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence
UniProt name L8AST2_9SYNC
Isoform
PDB entities 3
Chains and sequence ranges Author chain C; PDBConstruct 1–81; UniProt 1–81

Photosystem I subunit II

Synechocystis sp. PCC 6803

UniProt L8AFM8

State in the Current Structure

Assembly Physical composition Protein state Molecular copy count Associated components Data consistency
1 Protein heterocomplex Heteromer Protein 9 Photosystem I P700 chlorophyll a apoprotein A1 × 1 (L8AHT3) Photosystem I P700 chlorophyll a apoprotein A2 × 1 (L8AIC0) Photosystem I iron-sulfur center × 1 (L8AST2) Photosystem I reaction center subunit IV × 1 (L8ASH8) Photosystem I subunit III × 1 (L8AII8) Photosystem I reaction center subunit IX × 1 (L8AGL9) Photosystem I reaction center subunit PsaK × 1 (L8APJ0) Photosystem I reaction center subunit XII × 1 (L8ADF9) PHYLLOQUINONE × 2 IRON/SULFUR CLUSTER × 3 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 4 CHLOROPHYLL A ISOMER × 2 BETA-CAROTENE × 17 CHLOROPHYLL A × 90 DODECYL-ALPHA-D-MALTOSIDE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 1 CHLORIDE ION × 1 water × 4 Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence
UniProt name L8AFM8_9SYNC
Isoform
PDB entities 4
Chains and sequence ranges Author chain D; PDBConstruct 1–141; UniProt 1–141

Photosystem I reaction center subunit IV

Synechocystis sp. PCC 6803

UniProt L8ASH8

State in the Current Structure

Assembly Physical composition Protein state Molecular copy count Associated components Data consistency
1 Protein heterocomplex Heteromer Protein 9 Photosystem I P700 chlorophyll a apoprotein A1 × 1 (L8AHT3) Photosystem I P700 chlorophyll a apoprotein A2 × 1 (L8AIC0) Photosystem I iron-sulfur center × 1 (L8AST2) Photosystem I subunit II × 1 (L8AFM8) Photosystem I subunit III × 1 (L8AII8) Photosystem I reaction center subunit IX × 1 (L8AGL9) Photosystem I reaction center subunit PsaK × 1 (L8APJ0) Photosystem I reaction center subunit XII × 1 (L8ADF9) PHYLLOQUINONE × 2 IRON/SULFUR CLUSTER × 3 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 4 CHLOROPHYLL A ISOMER × 2 BETA-CAROTENE × 17 CHLOROPHYLL A × 90 DODECYL-ALPHA-D-MALTOSIDE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 1 CHLORIDE ION × 1 water × 4 Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence
UniProt name L8ASH8_9SYNC
Isoform
PDB entities 5
Chains and sequence ranges Author chain E; PDBConstruct 1–74; UniProt 1–74

Photosystem I subunit III

Synechocystis sp. PCC 6803

UniProt L8AII8

State in the Current Structure

Assembly Physical composition Protein state Molecular copy count Associated components Data consistency
1 Protein heterocomplex Heteromer Protein 9 Photosystem I P700 chlorophyll a apoprotein A1 × 1 (L8AHT3) Photosystem I P700 chlorophyll a apoprotein A2 × 1 (L8AIC0) Photosystem I iron-sulfur center × 1 (L8AST2) Photosystem I subunit II × 1 (L8AFM8) Photosystem I reaction center subunit IV × 1 (L8ASH8) Photosystem I reaction center subunit IX × 1 (L8AGL9) Photosystem I reaction center subunit PsaK × 1 (L8APJ0) Photosystem I reaction center subunit XII × 1 (L8ADF9) PHYLLOQUINONE × 2 IRON/SULFUR CLUSTER × 3 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 4 CHLOROPHYLL A ISOMER × 2 BETA-CAROTENE × 17 CHLOROPHYLL A × 90 DODECYL-ALPHA-D-MALTOSIDE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 1 CHLORIDE ION × 1 water × 4 Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence
UniProt name L8AII8_9SYNC
Isoform
PDB entities 6
Chains and sequence ranges Author chain F; PDBConstruct 1–165; UniProt 20–184

Photosystem I reaction center subunit IX

Synechocystis sp. PCC 6803

UniProt L8AGL9

State in the Current Structure

Assembly Physical composition Protein state Molecular copy count Associated components Data consistency
1 Protein heterocomplex Heteromer Protein 9 Photosystem I P700 chlorophyll a apoprotein A1 × 1 (L8AHT3) Photosystem I P700 chlorophyll a apoprotein A2 × 1 (L8AIC0) Photosystem I iron-sulfur center × 1 (L8AST2) Photosystem I subunit II × 1 (L8AFM8) Photosystem I reaction center subunit IV × 1 (L8ASH8) Photosystem I subunit III × 1 (L8AII8) Photosystem I reaction center subunit PsaK × 1 (L8APJ0) Photosystem I reaction center subunit XII × 1 (L8ADF9) PHYLLOQUINONE × 2 IRON/SULFUR CLUSTER × 3 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 4 CHLOROPHYLL A ISOMER × 2 BETA-CAROTENE × 17 CHLOROPHYLL A × 90 DODECYL-ALPHA-D-MALTOSIDE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 1 CHLORIDE ION × 1 water × 4 Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence
UniProt name L8AGL9_9SYNC
Isoform
PDB entities 7
Chains and sequence ranges Author chain J; PDBConstruct 1–40; UniProt 1–40

Photosystem I reaction center subunit PsaK

Synechocystis sp. PCC 6803

UniProt L8APJ0

State in the Current Structure

Assembly Physical composition Protein state Molecular copy count Associated components Data consistency
1 Protein heterocomplex Heteromer Protein 9 Photosystem I P700 chlorophyll a apoprotein A1 × 1 (L8AHT3) Photosystem I P700 chlorophyll a apoprotein A2 × 1 (L8AIC0) Photosystem I iron-sulfur center × 1 (L8AST2) Photosystem I subunit II × 1 (L8AFM8) Photosystem I reaction center subunit IV × 1 (L8ASH8) Photosystem I subunit III × 1 (L8AII8) Photosystem I reaction center subunit IX × 1 (L8AGL9) Photosystem I reaction center subunit XII × 1 (L8ADF9) PHYLLOQUINONE × 2 IRON/SULFUR CLUSTER × 3 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 4 CHLOROPHYLL A ISOMER × 2 BETA-CAROTENE × 17 CHLOROPHYLL A × 90 DODECYL-ALPHA-D-MALTOSIDE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 1 CHLORIDE ION × 1 water × 4 Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence
UniProt name L8APJ0_9SYNC
Isoform
PDB entities 8
Chains and sequence ranges Author chain K; PDBConstruct 1–128; UniProt 1–128

Photosystem I reaction center subunit XII

Synechocystis sp. PCC 6803

UniProt L8ADF9

State in the Current Structure

Assembly Physical composition Protein state Molecular copy count Associated components Data consistency
1 Protein heterocomplex Heteromer Protein 9 Photosystem I P700 chlorophyll a apoprotein A1 × 1 (L8AHT3) Photosystem I P700 chlorophyll a apoprotein A2 × 1 (L8AIC0) Photosystem I iron-sulfur center × 1 (L8AST2) Photosystem I subunit II × 1 (L8AFM8) Photosystem I reaction center subunit IV × 1 (L8ASH8) Photosystem I subunit III × 1 (L8AII8) Photosystem I reaction center subunit IX × 1 (L8AGL9) Photosystem I reaction center subunit PsaK × 1 (L8APJ0) PHYLLOQUINONE × 2 IRON/SULFUR CLUSTER × 3 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE × 4 CHLOROPHYLL A ISOMER × 2 BETA-CAROTENE × 17 CHLOROPHYLL A × 90 DODECYL-ALPHA-D-MALTOSIDE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 1 CHLORIDE ION × 1 water × 4 Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence
UniProt name L8ADF9_9SYNC
Isoform
PDB entities 9
Chains and sequence ranges Author chain M; PDBConstruct 1–31; UniProt 1–31

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.

2. Structure Basics 2. Structure Basics

Entry ID entry_id4kt0
Deposition date deposition_date2013-05-19
Structure title titleCrystal structure of a virus like photosystem I from the cyanobacterium Synechocystis PCC 6803
Keywords keywordsphotosynthetic reaction center, membrane complex, plastocyanin, cytochrome C6, Ferredoxin, ELECTRON TRANSPORT; ELECTRON TRANSPORT
Experimental Method methodX-RAY DIFFRACTION

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.

4kt0__assembly_1__model_1

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

Download this curve (.dat)

4kt0__assembly_1__model_1 | I(q)

10-2 10-1 106 107 108 q (1/Angstrom) I(q)
100 plotted points; both axes use logarithmic scales.

4kt0__assembly_1__model_1 | P(r) · Pending

The new assembly/model P(r) has not been calculated yet This placeholder does not display legacy data r (Angstrom) P(r)
P(r) will be calculated and displayed separately for the same assembly/model.
Rg(Guinier)41.73 Å
Rg (electron density)40.53 Å
Total Rg41.02 Å
Atom count22022
Residues2017
Excluded volume410350 ų
Maximum q0.500 Å⁻¹
Assembly Model Structure unit Oligomeric description Status CRYSOL Actions
1 1 4kt0__assembly_1__model_1 nonameric (9) Success 4.1.3-1-20251215 (887e7ef) View Download

4. Crystallography and Experiment 4. Crystallography & Experiment

5. Entities and Polymers Entities & Polymers (19)

6. Fold Classification (SCOP + CATH) 15 domains

SCOP 2.08 (7 domains)

Domain ID domain_idd4kt0a_
Class classf — Membrane and cell surface proteins and peptides
Fold Fold foldf.29 — Photosystem I subunits PsaA/PsaB
Superfamily Superfamily superfamilyf.29.1 — Photosystem I subunits PsaA/PsaB
Family Family familyf.29.1.1 — Photosystem I subunits PsaA/PsaB
Domain ID domain_idd4kt0b_
Class classf — Membrane and cell surface proteins and peptides
Fold Fold foldf.29 — Photosystem I subunits PsaA/PsaB
Superfamily Superfamily superfamilyf.29.1 — Photosystem I subunits PsaA/PsaB
Family Family familyf.29.1.1 — Photosystem I subunits PsaA/PsaB
Domain ID domain_idd4kt0c_
Class classd — Alpha and beta proteins (a+b)
Fold Fold foldd.58 — Ferredoxin-like
Superfamily Superfamily superfamilyd.58.1 — 4Fe-4S ferredoxins
Family Family familyd.58.1.2 — 7-Fe ferredoxin
Domain ID domain_idd4kt0d_
Class classd — Alpha and beta proteins (a+b)
Fold Fold foldd.187 — Photosystem I subunit PsaD
Superfamily Superfamily superfamilyd.187.1 — Photosystem I subunit PsaD
Family Family familyd.187.1.1 — Photosystem I subunit PsaD
Domain ID domain_idd4kt0e_
Class classb — All beta proteins
Fold Fold foldb.34 — SH3-like barrel
Superfamily Superfamily superfamilyb.34.4 — Electron transport accessory proteins
Family Family familyb.34.4.2 — Photosystem I accessory protein E (PsaE)
Domain ID domain_idd4kt0f_
Class classf — Membrane and cell surface proteins and peptides
Fold Fold foldf.23 — Single transmembrane helix
Superfamily Superfamily superfamilyf.23.16 — Subunit III of photosystem I reaction centre, PsaF
Family Family familyf.23.16.1 — Subunit III of photosystem I reaction centre, PsaF
Domain ID domain_idd4kt0j_
Class classf — Membrane and cell surface proteins and peptides
Fold Fold foldf.23 — Single transmembrane helix
Superfamily Superfamily superfamilyf.23.18 — Subunit IX of photosystem I reaction centre, PsaJ
Family Family familyf.23.18.1 — Subunit IX of photosystem I reaction centre, PsaJ

CATH v4.4 (8 domains)

Domain ID domain_id4kt0A00
Class class1 — Mainly Alpha
Architecture architecture20 — Up-down Bundle
Topology topology1130 — Photosystem I p700 chlorophyll A apoprotein A1
Homologous superfamily homologous superfamily10 — Photosystem I PsaA/PsaB
Domain ID domain_id4kt0B00
Class class1 — Mainly Alpha
Architecture architecture20 — Up-down Bundle
Topology topology1130 — Photosystem I p700 chlorophyll A apoprotein A1
Homologous superfamily homologous superfamily10 — Photosystem I PsaA/PsaB
Domain ID domain_id4kt0C00
Class class3 — Alpha Beta
Architecture architecture30 — 2-Layer Sandwich
Topology topology70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily20
Domain ID domain_id4kt0D00
Class class3 — Alpha Beta
Architecture architecture30 — 2-Layer Sandwich
Topology topology1470 — Photosystem 1 Reaction Centre Subunit Ii; Chain: D;
Homologous superfamily homologous superfamily10 — Photosystem I PsaD, reaction center subunit II
Domain ID domain_id4kt0E00
Class class2 — Mainly Beta
Architecture architecture30 — Roll
Topology topology30 — SH3 type barrels.
Homologous superfamily homologous superfamily50
Domain ID domain_id4kt0F00
Class class1 — Mainly Alpha
Architecture architecture10 — Orthogonal Bundle
Topology topology8 — Helicase, Ruva Protein; domain 3
Homologous superfamily homologous superfamily110 — Photosystem I, reaction centre, subunit PsaF
Domain ID domain_id4kt0J00
Class class1 — Mainly Alpha
Architecture architecture20 — Up-down Bundle
Topology topology5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily510 — Single helix bin
Domain ID domain_id4kt0K00
Class class1 — Mainly Alpha
Architecture architecture20 — Up-down Bundle
Topology topology860 — Alpha-t-alpha
Homologous superfamily homologous superfamily20 — Photosystem I PsaK, reaction centre

7. Citations (1)