Structure of PDB 6xkx Chain C

Receptor sequence

>6xkxC (length=423) Species: 272942 (Rhodobacter capsulatus SB 1003)

SGIPHDHYEPKTGIEKWLHDRLPIVGLVYDTIMIPTPKNLNWWWIWGIVL
AFTLVLQIVTGIVLAMHYTPHVDLAFASVEHIMRDVNGGWAMRYIHANGA
SLFFLAVYIHIFRGLYYGSYKAPREITWIVGMVIYLLMMGTAFMGYVLPW
GQMSFWGATVITGLFGAIPGIGPSIQAWLLGGPAVDNATLNRFFSLHYLL
PFVIAALVAIHIWAFHTTGNNNPTGVEVRRTAEKDTLPFWPYFVIKDLFA
LALVLLGFFAVVAYMPNYLGHPDNYVQANPLSTPAHIVPEWYFLPFYAIL
RAFAADVWVVILVDGLTFGIVDAKFFGVIAMFGAIAVMALAPWLDTSKVR
SGAYRPKFRMWFWFLVLDFVVLTWVGAMPTEYPYDWISLIASTYWFAYFL
VILPLLGATEKPEPIPASIEEDF

3D structure

• PDB: 6xkx Cryo-EM structures of engineered active bc 1 -cbb 3 type CIII 2 CIV super-complexes and electronic communication between the complexes.
• Chain: C
• Resolution: 6.1 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): H217 N221 K251 D252 E295
• Catalytic site (residue number reindexed from 1): H216 N220 K246 D247 E290

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	C	G62 I63 L65 R94 H97 G146 L149 P150 H198 Y199	G61 I62 L64 R93 H96 G145 L148 P149 H197 Y198
BS02	HEC	C	G48 L51 F104 H111 I112 R114 R125 G132 M133 H212 F216 N221 N222	G47 L50 F103 H110 I111 R113 R124 G131 M132 H211 F215 N220 N221

Gene Ontology

Molecular Function

• GO:0008121 ubiquinol-cytochrome-c reductase activity
• GO:0009055 electron transfer activity
• GO:0016491 oxidoreductase activity
• GO:0046872 metal ion binding

Biological Process

• GO:0022904 respiratory electron transport chain
• GO:1902600 proton transmembrane transport

Cellular Component

• GO:0005886 plasma membrane
• GO:0016020 membrane
• GO:0045275 respiratory chain complex III

External links

• PDB: RCSB:6xkx, PDBe:6xkx, PDBj:6xkx
• PDBsum: 6xkx
• PubMed: 33568648
• UniProt: D5ANZ3|CYB_RHOCB Cytochrome b (Gene Name=petB)