Structure of PDB 1q90 Chain B

Receptor sequence

>1q90B (length=212) Species: 3055 (Chlamydomonas reinhardtii)

VYDWFEERLEIQAIADDITSKYVPPHVNIFYCIGGITFTCFLVQVATGFA
MTFYYRPTVAEAFASVQYIMTDVNFGWLIRSIHRWSASMMVLMMVLHVFR
VYLTGGFKRPRELTWVTGVIMAVCTVSFGVTGYSLPWDQVGYWAVKIVTG
VPDAIPGVGGFIVELLRGGVGVGQATLTRFYSLHTFVLPLLTAVFMLMHF
LMIRKQGISGPL

3D structure

• PDB: 1q90 An Atypical Haem in the Cytochrome B6F Complex
• Chain: B
• Resolution: 3.1 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): R207 I211
• Catalytic site (residue number reindexed from 1): R204 I208

Interaction with ligand

Site #	Ligand	Ligand chain	Binding residues on receptor (original residue number in PDB)	Binding residues on receptor (residue number reindexed from 1)	Binding affinity
BS01	HEC	B	Y34 C35 G38 F203 R207 G210 I211	Y31 C32 G35 F200 R204 G207 I208
BS02	HEC	B	Y34 G37 T40 F41 H100 R103 V104 G109 T117 W118 G121 V122 M124 H202 I206 I211 S212	Y31 G34 T37 F38 H97 R100 V101 G106 T114 W115 G118 V119 M121 H199 I203 I208 S209
BS03	HEC	B	Q47 G51 F52 M54 R83 H86 R87 A90 F131 G135 Y136 L138 H187 T188 P192	Q44 G48 F49 M51 R80 H83 R84 A87 F128 G132 Y133 L135 H184 T185 P189
BS04	BCR	B	I32 F33 I39 M96	I29 F30 I36 M93
BS05	CLA	B	Y105 S130 V133	Y102 S127 V130
BS06	TDS	B	A147 I150 V151	A144 I147 V148

Gene Ontology

Molecular Function

• GO:0009055 electron transfer activity
• GO:0016491 oxidoreductase activity
• GO:0045158 electron transporter, transferring electrons within cytochrome b6/f complex of photosystem II activity
• GO:0046872 metal ion binding

Biological Process

• GO:0015979 photosynthesis
• GO:0022904 respiratory electron transport chain

Cellular Component

• GO:0009507 chloroplast
• GO:0009535 chloroplast thylakoid membrane
• GO:0009579 thylakoid
• GO:0016020 membrane

External links

• PDB: RCSB:1q90, PDBe:1q90, PDBj:1q90
• PDBsum: 1q90
• PubMed: 14647374
• UniProt: Q00471|CYB6_CHLRE Cytochrome b6 (Gene Name=petB)