1q90

Structure of the cytochrome b6f (plastohydroquinone : plastocyanin oxidoreductase) from Chlamydomonas reinhardtii

Method: X-RAY DIFFRACTION

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

Apocytochrome f

Chlamydomonas reinhardtii

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 18	Cytochrome b6 × 2 （Q00471） Cytochrome B6-F complex iron-sulfur subunit × 2 （P49728） Cytochrome b6-f complex subunit 4 × 2 （Q42496） Cytochrome B6-F complex iron-sulfur subunit × 2 （P23230） Cytochrome b6f complex subunit petG × 2 （P49728） Cytochrome b6f complex subunit petL × 2 （P50369） Cytochrome b6f complex subunit PETM × 2 （Q08362） Cytochrome b6f complex subunit PETN × 2 （P50369） HEME C × 8 BETA-CAROTENE × 2 EICOSANE × 2 FE2/S2 (INORGANIC) CLUSTER × 2 CHLOROPHYLL A × 2 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 4 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 2 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 36	Cytochrome b6 × 4 （Q00471） Cytochrome B6-F complex iron-sulfur subunit × 4 （P49728） Cytochrome b6-f complex subunit 4 × 4 （Q42496） Cytochrome B6-F complex iron-sulfur subunit × 4 （P23230） Cytochrome b6f complex subunit petG × 4 （P49728） Cytochrome b6f complex subunit petL × 4 （P50369） Cytochrome b6f complex subunit PETM × 4 （Q08362） Cytochrome b6f complex subunit PETN × 4 （P50369） HEME C × 16 BETA-CAROTENE × 4 EICOSANE × 4 FE2/S2 (INORGANIC) CLUSTER × 4 CHLOROPHYLL A × 4 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 8 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CYF_CHLRE
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–286； UniProt 32–317

Cytochrome b6

Chlamydomonas reinhardtii

UniProt Q00471

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 18	Apocytochrome f × 2 （P23577） Cytochrome B6-F complex iron-sulfur subunit × 2 （P49728） Cytochrome b6-f complex subunit 4 × 2 （Q42496） Cytochrome B6-F complex iron-sulfur subunit × 2 （P23230） Cytochrome b6f complex subunit petG × 2 （P49728） Cytochrome b6f complex subunit petL × 2 （P50369） Cytochrome b6f complex subunit PETM × 2 （Q08362） Cytochrome b6f complex subunit PETN × 2 （P50369） HEME C × 8 BETA-CAROTENE × 2 EICOSANE × 2 FE2/S2 (INORGANIC) CLUSTER × 2 CHLOROPHYLL A × 2 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 4 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 2 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 36	Apocytochrome f × 4 （P23577） Cytochrome B6-F complex iron-sulfur subunit × 4 （P49728） Cytochrome b6-f complex subunit 4 × 4 （Q42496） Cytochrome B6-F complex iron-sulfur subunit × 4 （P23230） Cytochrome b6f complex subunit petG × 4 （P49728） Cytochrome b6f complex subunit petL × 4 （P50369） Cytochrome b6f complex subunit PETM × 4 （Q08362） Cytochrome b6f complex subunit PETN × 4 （P50369） HEME C × 16 BETA-CAROTENE × 4 EICOSANE × 4 FE2/S2 (INORGANIC) CLUSTER × 4 CHLOROPHYLL A × 4 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 8 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CYB6_CHLRE
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–215； UniProt 1–215

Cytochrome B6-F complex iron-sulfur subunit

Chlamydomonas reinhardtii

UniProt P49728

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 18	Apocytochrome f × 2 （P23577） Cytochrome b6 × 2 （Q00471） Cytochrome b6-f complex subunit 4 × 2 （Q42496） Cytochrome B6-F complex iron-sulfur subunit × 2 （P23230） Cytochrome b6f complex subunit petL × 2 （P50369） Cytochrome b6f complex subunit PETM × 2 （Q08362） Cytochrome b6f complex subunit PETN × 2 （P50369） HEME C × 8 BETA-CAROTENE × 2 EICOSANE × 2 FE2/S2 (INORGANIC) CLUSTER × 2 CHLOROPHYLL A × 2 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 4 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 2 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 36	Apocytochrome f × 4 （P23577） Cytochrome b6 × 4 （Q00471） Cytochrome b6-f complex subunit 4 × 4 （Q42496） Cytochrome B6-F complex iron-sulfur subunit × 4 （P23230） Cytochrome b6f complex subunit petL × 4 （P50369） Cytochrome b6f complex subunit PETM × 4 （Q08362） Cytochrome b6f complex subunit PETN × 4 （P50369） HEME C × 16 BETA-CAROTENE × 4 EICOSANE × 4 FE2/S2 (INORGANIC) CLUSTER × 4 CHLOROPHYLL A × 4 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 8 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	UCRIA_CHLRE
Isoform	—
PDB entities	3, 6
Chains and sequence ranges	Author chain C； PDBConstruct 1–127； UniProt 80–206 Author chain G； PDBConstruct 1–37； UniProt 1–37

Cytochrome b6-f complex subunit 4

Chlamydomonas reinhardtii

UniProt Q42496

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 18	Apocytochrome f × 2 （P23577） Cytochrome b6 × 2 （Q00471） Cytochrome B6-F complex iron-sulfur subunit × 2 （P49728） Cytochrome B6-F complex iron-sulfur subunit × 2 （P23230） Cytochrome b6f complex subunit petG × 2 （P49728） Cytochrome b6f complex subunit petL × 2 （P50369） Cytochrome b6f complex subunit PETM × 2 （Q08362） Cytochrome b6f complex subunit PETN × 2 （P50369） HEME C × 8 BETA-CAROTENE × 2 EICOSANE × 2 FE2/S2 (INORGANIC) CLUSTER × 2 CHLOROPHYLL A × 2 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 4 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 2 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 36	Apocytochrome f × 4 （P23577） Cytochrome b6 × 4 （Q00471） Cytochrome B6-F complex iron-sulfur subunit × 4 （P49728） Cytochrome B6-F complex iron-sulfur subunit × 4 （P23230） Cytochrome b6f complex subunit petG × 4 （P49728） Cytochrome b6f complex subunit petL × 4 （P50369） Cytochrome b6f complex subunit PETM × 4 （Q08362） Cytochrome b6f complex subunit PETN × 4 （P50369） HEME C × 16 BETA-CAROTENE × 4 EICOSANE × 4 FE2/S2 (INORGANIC) CLUSTER × 4 CHLOROPHYLL A × 4 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 8 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PETM_CHLRE
Isoform	—
PDB entities	4
Chains and sequence ranges	Author chain D； PDBConstruct 1–159； UniProt 1–159

Cytochrome B6-F complex iron-sulfur subunit

Chlamydomonas reinhardtii

UniProt P23230

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 18	Apocytochrome f × 2 （P23577） Cytochrome b6 × 2 （Q00471） Cytochrome B6-F complex iron-sulfur subunit × 2 （P49728） Cytochrome b6-f complex subunit 4 × 2 （Q42496） Cytochrome b6f complex subunit petG × 2 （P49728） Cytochrome b6f complex subunit petL × 2 （P50369） Cytochrome b6f complex subunit PETM × 2 （Q08362） Cytochrome b6f complex subunit PETN × 2 （P50369） HEME C × 8 BETA-CAROTENE × 2 EICOSANE × 2 FE2/S2 (INORGANIC) CLUSTER × 2 CHLOROPHYLL A × 2 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 4 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 2 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 36	Apocytochrome f × 4 （P23577） Cytochrome b6 × 4 （Q00471） Cytochrome B6-F complex iron-sulfur subunit × 4 （P49728） Cytochrome b6-f complex subunit 4 × 4 （Q42496） Cytochrome b6f complex subunit petG × 4 （P49728） Cytochrome b6f complex subunit petL × 4 （P50369） Cytochrome b6f complex subunit PETM × 4 （Q08362） Cytochrome b6f complex subunit PETN × 4 （P50369） HEME C × 16 BETA-CAROTENE × 4 EICOSANE × 4 FE2/S2 (INORGANIC) CLUSTER × 4 CHLOROPHYLL A × 4 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 8 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PETD_CHLRE
Isoform	—
PDB entities	5
Chains and sequence ranges	Author chain R； PDBConstruct 1–49； UniProt 31–79

Cytochrome b6f complex subunit petL

Chlamydomonas reinhardtii

UniProt P50369

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 18	Apocytochrome f × 2 （P23577） Cytochrome b6 × 2 （Q00471） Cytochrome B6-F complex iron-sulfur subunit × 2 （P49728） Cytochrome b6-f complex subunit 4 × 2 （Q42496） Cytochrome B6-F complex iron-sulfur subunit × 2 （P23230） Cytochrome b6f complex subunit petG × 2 （P49728） Cytochrome b6f complex subunit PETM × 2 （Q08362） HEME C × 8 BETA-CAROTENE × 2 EICOSANE × 2 FE2/S2 (INORGANIC) CLUSTER × 2 CHLOROPHYLL A × 2 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 4 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 2 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 36	Apocytochrome f × 4 （P23577） Cytochrome b6 × 4 （Q00471） Cytochrome B6-F complex iron-sulfur subunit × 4 （P49728） Cytochrome b6-f complex subunit 4 × 4 （Q42496） Cytochrome B6-F complex iron-sulfur subunit × 4 （P23230） Cytochrome b6f complex subunit petG × 4 （P49728） Cytochrome b6f complex subunit PETM × 4 （Q08362） HEME C × 16 BETA-CAROTENE × 4 EICOSANE × 4 FE2/S2 (INORGANIC) CLUSTER × 4 CHLOROPHYLL A × 4 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 8 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PETL_CHLRE
Isoform	—
PDB entities	7, 9
Chains and sequence ranges	Author chain L； PDBConstruct 1–32； UniProt 12–43 Author chain N； PDBConstruct 1–31； UniProt 68–98

Cytochrome b6f complex subunit PETM

Chlamydomonas reinhardtii

UniProt Q08362

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 18	Apocytochrome f × 2 （P23577） Cytochrome b6 × 2 （Q00471） Cytochrome B6-F complex iron-sulfur subunit × 2 （P49728） Cytochrome b6-f complex subunit 4 × 2 （Q42496） Cytochrome B6-F complex iron-sulfur subunit × 2 （P23230） Cytochrome b6f complex subunit petG × 2 （P49728） Cytochrome b6f complex subunit petL × 2 （P50369） Cytochrome b6f complex subunit PETN × 2 （P50369） HEME C × 8 BETA-CAROTENE × 2 EICOSANE × 2 FE2/S2 (INORGANIC) CLUSTER × 2 CHLOROPHYLL A × 2 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 2 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 4 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 2 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 36	Apocytochrome f × 4 （P23577） Cytochrome b6 × 4 （Q00471） Cytochrome B6-F complex iron-sulfur subunit × 4 （P49728） Cytochrome b6-f complex subunit 4 × 4 （Q42496） Cytochrome B6-F complex iron-sulfur subunit × 4 （P23230） Cytochrome b6f complex subunit petG × 4 （P49728） Cytochrome b6f complex subunit petL × 4 （P50369） Cytochrome b6f complex subunit PETN × 4 （P50369） HEME C × 16 BETA-CAROTENE × 4 EICOSANE × 4 FE2/S2 (INORGANIC) CLUSTER × 4 CHLOROPHYLL A × 4 8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE × 4 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE × 8 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PETG_CHLRE
Isoform	—
PDB entities	8
Chains and sequence ranges	Author chain M； PDBConstruct 1–39； UniProt 61–99

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	1q90
Deposition date deposition_date	2003-08-22
Structure title title	Structure of the cytochrome b6f (plastohydroquinone : plastocyanin oxidoreductase) from Chlamydomonas reinhardtii
Keywords keywords	;MEMBRANE PROTEIN COMPLEX, PHOTOSYNTHESIS, ELECTRON TRANSFER, OXYDOREDUCTASE, CHLOROPHYLL, BETA-CAROTENE, STIGMATELLIN, SULFOQUINOVOSYLDIACYLGLYCEROL, MONOGALACTOSYLDIACYLGLYCEROL ;; PHOTOSYNTHESIS
Experimental Method method	X-RAY DIFFRACTION

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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.

1q90__assembly_1__model_1

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

Download this curve (.dat)

1q90__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1q90__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	42.80 Å
Rg (electron density)	41.73 Å
Total Rg	42.09 Å
Atom count	15552
Residues	1904
Excluded volume	285390 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1q90__assembly_1__model_1`	octadecameric （18）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1q90__assembly_2__model_1`	36-meric （36）	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 (18)

Entity 1 Entity 1 polymer

Description description	Apocytochrome f
Molecular weight formula_weight	32109.8 kDa
Mutation mutation	6 His tag at C-terminus
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	7778

YPVFAQQNYANPREANGRIVCANCHLAQKAVEIEVPQAVLPDTVFEAVIELPYDKQVKQVLANGKKGDLNVGMVLILPEGFELAPPDRVPAEIKEKVGNLYYQPYSPEQKNILVVGPVPGKKYSEMVVPILSPDPAKNKNVSYLKYPIYFGGNRGRGQVYPDGKKSNNTIYNASAAGKIVAITALSEKKGGFEVSIEKANGEVVVDKIPAGPDLIVKEGQTVQADQPLTNNPNVGGFGQAETEIVLQNPARIQGLLVFFSFVLLTQVLLVLKKKQFEKVQLAEMNFHHHHHH

Source Source

Source organism organism	Chlamydomonas reinhardtii
NCBI taxonomy ID ncbi_taxonomy_id	3055
Host organism host_organism	Chlamydomonas reinhardtii

Entity 2 Entity 2 polymer

Description description	Cytochrome b6
Molecular weight formula_weight	24184.5 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B

MSKVYDWFEERLEIQAIADDITSKYVPPHVNIFYCIGGITFTCFLVQVATGFAMTFYYRPTVAEAFASVQYIMTDVNFGWLIRSIHRWSASMMVLMMVLHVFRVYLTGGFKRPRELTWVTGVIMAVCTVSFGVTGYSLPWDQVGYWAVKIVTGVPDAIPGVGGFIVELLRGGVGVGQATLTRFYSLHTFVLPLLTAVFMLMHFLMIRKQGISGPL

Source Source

Source organism organism	Chlamydomonas reinhardtii
NCBI taxonomy ID ncbi_taxonomy_id	3055
Host organism host_organism	Chlamydomonas reinhardtii

Entity 3 Entity 3 polymer

Description description	Cytochrome B6-F complex iron-sulfur subunit
Molecular weight formula_weight	13660.4 kDa
EC 编号 ec_number	1.10.99.1
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	C

QAAKDALGNDIKAGEWLKTHLAGDRSLSQGLKGDPTYLIVTADSTIEKYGLNAVCTHLGCVVPWVAAENKFKCPCHGSQYNAEGKVVRGPAPLSLALAHCDVAESGLVTFSTWTETDFRTGLEPWWA

Source Source

Source organism organism	Chlamydomonas reinhardtii
NCBI taxonomy ID ncbi_taxonomy_id	3055
Host organism host_organism	Chlamydomonas reinhardtii

Entity 4 Entity 4 polymer

Description description	Cytochrome b6-f complex subunit 4
Molecular weight formula_weight	17305.6 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	D

MSVTKKPDLSDPVLKAKLAKGMGHNTYGEPAWPNDLLYMFPVVILGTFACVIGLSVLDPAAMGEPANPFATPLEILPEWYFYPVFQILRVVPNKLLGVLLMAAVPAGLITVPFIESINKFQNPYRRPIATILFLLGTLVAVWLGIGSTFPIDISLTLGL

Source Source

Source organism organism	Chlamydomonas reinhardtii
NCBI taxonomy ID ncbi_taxonomy_id	3055
Host organism host_organism	Chlamydomonas reinhardtii

Entity 5 Entity 5 polymer

Description description	Cytochrome B6-F complex iron-sulfur subunit
Molecular weight formula_weight	4707.3 kDa
EC 编号 ec_number	1.10.99.1
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	R

AASSEVPDMNKRNIMNLILAGGAGLPITTLALGYGAFFVPPSSGGGGGG

Source Source

Source organism organism	Chlamydomonas reinhardtii
NCBI taxonomy ID ncbi_taxonomy_id	3055
Host organism host_organism	Chlamydomonas reinhardtii

Entity 6 Entity 6 polymer

Description description	Cytochrome b6f complex subunit petG
Molecular weight formula_weight	3984.8 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	G

MVEPLLCGIVLGLVPVTIAGLFVTAYLQYLRGDLATY

Source Source

Source organism organism	Chlamydomonas reinhardtii
NCBI taxonomy ID ncbi_taxonomy_id	3055
Host organism host_organism	Chlamydomonas reinhardtii

Entity 7 Entity 7 polymer

Description description	Cytochrome b6f complex subunit petL
Molecular weight formula_weight	3438.3 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	L

MLTITSYVGLLIGALVFTLGIYLGLLKVVKLI

Source Source

Source organism organism	Chlamydomonas reinhardtii
NCBI taxonomy ID ncbi_taxonomy_id	3055
Host organism host_organism	Chlamydomonas reinhardtii

Entity 8 Entity 8 polymer

Description description	Cytochrome b6f complex subunit PETM
Molecular weight formula_weight	4037.8 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	M

GEAEFIAGTALTMVGMTLVGLAIGFVLLRVESLVEEGKI

Source Source

Source organism organism	Chlamydomonas reinhardtii
NCBI taxonomy ID ncbi_taxonomy_id	3055
Host organism host_organism	Chlamydomonas reinhardtii

Entity 9 Entity 9 polymer

Description description	Cytochrome b6f complex subunit PETN
Molecular weight formula_weight	3283.8 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	N

GEPAIVQIGWAATCVMFSFSLSLVVWGRSGL

Source Source

Source organism organism	Chlamydomonas reinhardtii
NCBI taxonomy ID ncbi_taxonomy_id	3055
Host organism host_organism	Chlamydomonas reinhardtii

Entity 10 Entity 10 non-polymer

Description description	HEME C
Molecular weight formula_weight	618.5 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 11 Entity 11 non-polymer

Description description	BETA-CAROTENE
Molecular weight formula_weight	536.9 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 12 Entity 12 non-polymer

Description description	EICOSANE
Molecular weight formula_weight	282.5 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 13 Entity 13 non-polymer

Description description	FE2/S2 (INORGANIC) CLUSTER
Molecular weight formula_weight	175.8 kDa
Source method src_method	syn
Copy count entity_count	1

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	1

Entity 15 Entity 15 non-polymer

Description description	8-HYDROXY-5,7-DIMETHOXY-3-METHYL-2-TRIDECYL-4H-CHROMEN-4-ONE
Molecular weight formula_weight	418.6 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 16 Entity 16 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	2

Entity 17 Entity 17 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	1

Entity 18 Entity 18 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	2

▼

6. Fold Classification (SCOP + CATH) 18 domains

SCOP 2.08 (12 domains)

Domain ID domain_id	d1q90a1
Class class	b — All beta proteins
Fold Fold fold	b.2 — Common fold of diphtheria toxin/transcription factors/cytochrome f
Superfamily Superfamily superfamily	b.2.6 — Cytochrome f, large domain
Family Family family	b.2.6.1 — Cytochrome f, large domain

Domain ID domain_id	d1q90a2
Class class	b — All beta proteins
Fold Fold fold	b.84 — Barrel-sandwich hybrid
Superfamily Superfamily superfamily	b.84.2 — Rudiment single hybrid motif
Family Family family	b.84.2.2 — Cytochrome f, small domain

Domain ID domain_id	d1q90a3
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.23 — Single transmembrane helix
Superfamily Superfamily superfamily	f.23.23 — Cytochrome f subunit of the cytochrome b6f complex, transmembrane anchor
Family Family family	f.23.23.1 — Cytochrome f subunit of the cytochrome b6f complex, transmembrane anchor

Domain ID domain_id	d1q90a4
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

Domain ID domain_id	d1q90b_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.21 — Heme-binding four-helical bundle
Superfamily Superfamily superfamily	f.21.1 — Transmembrane di-heme cytochromes
Family Family family	f.21.1.2 — Cytochrome b of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase)

Domain ID domain_id	d1q90c_
Class class	b — All beta proteins
Fold Fold fold	b.33 — ISP domain
Superfamily Superfamily superfamily	b.33.1 — ISP domain
Family Family family	b.33.1.1 — Rieske iron-sulfur protein (ISP)

Domain ID domain_id	d1q90d_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.32 — a domain/subunit of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase)
Superfamily Superfamily superfamily	f.32.1 — a domain/subunit of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase)
Family Family family	f.32.1.1 — a domain/subunit of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase)

Domain ID domain_id	d1q90g_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.23 — Single transmembrane helix
Superfamily Superfamily superfamily	f.23.26 — PetG subunit of the cytochrome b6f complex
Family Family family	f.23.26.1 — PetG subunit of the cytochrome b6f complex

Domain ID domain_id	d1q90l_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.23 — Single transmembrane helix
Superfamily Superfamily superfamily	f.23.24 — PetL subunit of the cytochrome b6f complex
Family Family family	f.23.24.1 — PetL subunit of the cytochrome b6f complex

Domain ID domain_id	d1q90m_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.23 — Single transmembrane helix
Superfamily Superfamily superfamily	f.23.25 — PetM subunit of the cytochrome b6f complex
Family Family family	f.23.25.1 — PetM subunit of the cytochrome b6f complex

Domain ID domain_id	d1q90n_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.23 — Single transmembrane helix
Superfamily Superfamily superfamily	f.23.27 — PetN subunit of the cytochrome b6f complex
Family Family family	f.23.27.1 — PetN subunit of the cytochrome b6f complex

Domain ID domain_id	d1q90r_
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.23 — Single transmembrane helix
Superfamily Superfamily superfamily	f.23.12 — ISP transmembrane anchor
Family Family family	f.23.12.1 — ISP transmembrane anchor

CATH v4.4 (6 domains)

Domain ID domain_id	1q90A01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	830 — Cytochrome f large domain

Domain ID domain_id	1q90A02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	100 — RNA polymerase II/Efflux pump adaptor protein, barrel-sandwich hybrid domain

Domain ID domain_id	1q90B00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	810 — Cytochrome Bc1 Complex; Chain C
Homologous superfamily homologous superfamily	10 — Cytochrome Bc1 Complex; Chain C

Domain ID domain_id	1q90C00
Class class	2 — Mainly Beta
Architecture architecture	102 — 3-layer Sandwich
Topology topology	10 — Rieske Iron-sulfur Protein
Homologous superfamily homologous superfamily	10 — Rieske [2Fe-2S] iron-sulphur domain

Domain ID domain_id	1q90D01
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	1q90D02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	980 — plastocyanin oxidoreductase

▶

Unit-cell length a length_a	102.454 Å
Unit-cell length b length_b	171.205 Å
Unit-cell length c length_c	351.009 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	8

Space group space_group	I 2 2 2
Space-group number int_tables_number	23
Crystal system crystal_system	—

Resolution resolution	3.100 Å
Low-resolution limit resolution_low	34.420 Å
R factor r_factor	0.2220
R_work r_work	0.2220
R_free r_free	0.2610

Structure of the cytochrome b6f (plastohydroquinone : plastocyanin oxidoreductase) from Chlamydomonas reinhardtii

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

Apocytochrome f

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Cytochrome b6

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Cytochrome B6-F complex iron-sulfur subunit

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Cytochrome b6-f complex subunit 4

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Cytochrome B6-F complex iron-sulfur subunit

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Cytochrome b6f complex subunit petL

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Cytochrome b6f complex subunit PETM

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

1q90__assembly_1__model_1

1q90__assembly_1__model_1 | I(q)

1q90__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction

5. Entities and Polymers Entities & Polymers (18)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 polymer

Polymer Polymer