Function and Biology

Zinc ion binding structure of bovine heart cytochrome C oxidase in the fully reduced state

EC 7.1.1.9: Cytochrome-c oxidase

Reaction catalysed:
4 ferrocytochrome c + O(2) + 4 H(+) = 4 ferricytochrome c + 2 H(2)O
Systematic name:
Ferrocytochrome-c:oxygen oxidoreductase
Alternative Name(s):
  • Complex IV (mitochondrial electron transport)
  • Cytochrome a3
  • Cytochrome aa3
  • Cytochrome ba(3)
  • Cytochrome bb3
  • Cytochrome caa(3)
  • Cytochrome cbb(3)
  • Cytochrome oxidase
  • Ferrocytochrome c oxidase
  • Indophenol oxidase
  • Indophenolase
  • NADH cytochrome c oxidase
  • Warburg's respiratory enzyme

Sequence families

Pfam Protein families (Pfam)
PF02936
Domain description: Cytochrome c oxidase subunit IV
Occurring in:
  1. Cytochrome c oxidase subunit 4 isoform 1, mitochondrial
1 copy of Pfam domain PF02936 (Cytochrome c oxidase subunit IV) in Cytochrome c oxidase subunit 4 isoform 1, mitochondrial in PDB 2eim.

PF00510
Domain description: Cytochrome c oxidase subunit III
Occurring in:
  1. Cytochrome c oxidase subunit 3
1 copy of Pfam domain PF00510 (Cytochrome c oxidase subunit III) in Cytochrome c oxidase subunit 3 in PDB 2eim.

PF00115
Domain description: Cytochrome C and Quinol oxidase polypeptide I
Occurring in:
  1. Cytochrome c oxidase subunit 1
1 copy of Pfam domain PF00115 (Cytochrome C and Quinol oxidase polypeptide I) in Cytochrome c oxidase subunit 1 in PDB 2eim.

PF02297
Domain description: Cytochrome oxidase c subunit VIb
Occurring in:
  1. Cytochrome c oxidase subunit 6B1
1 copy of Pfam domain PF02297 (Cytochrome oxidase c subunit VIb) in Cytochrome c oxidase subunit 6B1 in PDB 2eim.

PF00116
Domain description: Cytochrome C oxidase subunit II, periplasmic domain
Occurring in:
  1. Cytochrome c oxidase subunit 2
1 copy of Pfam domain PF00116 (Cytochrome C oxidase subunit II, periplasmic domain) in Cytochrome c oxidase subunit 2 in PDB 2eim.

PF02284
Domain description: Cytochrome c oxidase subunit Va
Occurring in:
  1. Cytochrome c oxidase subunit 5A, mitochondrial
1 copy of Pfam domain PF02284 (Cytochrome c oxidase subunit Va) in Cytochrome c oxidase subunit 5A, mitochondrial in PDB 2eim.

PF02285
Domain description: Cytochrome oxidase c subunit VIII
Occurring in:
  1. Cytochrome c oxidase subunit 8B, mitochondrial
1 copy of Pfam domain PF02285 (Cytochrome oxidase c subunit VIII) in Cytochrome c oxidase subunit 8B, mitochondrial in PDB 2eim.

PF02790
Domain description: Cytochrome C oxidase subunit II, transmembrane domain
Occurring in:
  1. Cytochrome c oxidase subunit 2
1 copy of Pfam domain PF02790 (Cytochrome C oxidase subunit II, transmembrane domain) in Cytochrome c oxidase subunit 2 in PDB 2eim.

PF02937
Domain description: Cytochrome c oxidase subunit VIc
Occurring in:
  1. Cytochrome c oxidase subunit 6C
1 copy of Pfam domain PF02937 (Cytochrome c oxidase subunit VIc) in Cytochrome c oxidase subunit 6C in PDB 2eim.

PF02238
Domain description: Cytochrome c oxidase subunit VII
Occurring in:
  1. Cytochrome c oxidase subunit 7A1, mitochondrial
1 copy of Pfam domain PF02238 (Cytochrome c oxidase subunit VII) in Cytochrome c oxidase subunit 7A1, mitochondrial in PDB 2eim.

InterPro InterPro annotations
IPR000883
Domain description: Cytochrome c oxidase subunit I
Occurring in:
  1. Cytochrome c oxidase subunit 1
IPR001349
Domain description: Cytochrome c oxidase, subunit VIa
Occurring in:
  1. Cytochrome c oxidase subunit 6A2, mitochondrial
IPR013288
Domain description: Cytochrome c oxidase subunit IV
Occurring in:
  1. Cytochrome c oxidase subunit 4 isoform 1, mitochondrial
IPR004203
Domain description: Cytochrome c oxidase subunit IV family
Occurring in:
  1. Cytochrome c oxidase subunit 4 isoform 1, mitochondrial
IPR003204
Domain description: Cytochrome c oxidase, subunit Va/VI
Occurring in:
  1. Cytochrome c oxidase subunit 5A, mitochondrial
IPR002124
Domain description: Cytochrome c oxidase, subunit Vb
Occurring in:
  1. Cytochrome c oxidase subunit 5B, mitochondrial
IPR008433
Domain description: Cytochrome C oxidase, subunit VIIB
Occurring in:
  1. Cytochrome c oxidase subunit 7B, mitochondrial
IPR003213
Domain description: Cytochrome c oxidase, subunit VIb
Occurring in:
  1. Cytochrome c oxidase subunit 6B1
IPR037169
Domain description: Mitochondrial cytochrome c oxidase subunit VIc/VIIs superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 6C
IPR036639
Domain description: Cytochrome c oxidase subunit IV superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 4 isoform 1, mitochondrial
IPR036539
Domain description: Cytochrome c oxidase, subunit VIIa superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 7A1, mitochondrial
IPR003177
Domain description: Cytochrome c oxidase subunit VIIa, metazoa
Occurring in:
  1. Cytochrome c oxidase subunit 7A1, mitochondrial
IPR036418
Domain description: Cytochrome c oxidase, subunit VIa superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 6A2, mitochondrial
IPR003205
Domain description: Cytochrome c oxidase, subunit 8
Occurring in:
  1. Cytochrome c oxidase subunit 8B, mitochondrial
IPR036927
Domain description: Cytochrome c oxidase-like, subunit I superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 1
IPR036549
Domain description: Cytochrome c oxidase, subunit VIb superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 6B1
IPR036548
Domain description: Cytochrome c oxidase, subunit 8 superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 8B, mitochondrial
IPR036257
Domain description: Cytochrome C oxidase subunit II, transmembrane domain superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 2
IPR036545
Domain description: Cytochrome c oxidase, subunit Va/VI superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 5A, mitochondrial
IPR008972
Domain description: Cupredoxin
Occurring in:
  1. Cytochrome c oxidase subunit 2
IPR023272
Domain description: Cytochrome C oxidase, subunit VIIB domain superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 7B, mitochondrial
IPR004202
Domain description: Cytochrome c oxidase subunit VIIc
Occurring in:
  1. Cytochrome c oxidase subunit 7C, mitochondrial
IPR004204
Domain description: Cytochrome c oxidase subunit 6C
Occurring in:
  1. Cytochrome c oxidase subunit 6C
IPR033944
Domain description: Cytochrome c oxidase subunit I domain
Occurring in:
  1. Cytochrome c oxidase subunit 1
IPR036972
Domain description: Cytochrome c oxidase, subunit Vb superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 5B, mitochondrial
IPR036636
Domain description: Cytochrome c oxidase subunit VIIc superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 7C, mitochondrial
IPR013833
Domain description: Cytochrome c oxidase, subunit III, 4-helical bundle
Occurring in:
  1. Cytochrome c oxidase subunit 3
IPR039297
Domain description: Cytochrome c oxidase subunit VII
Occurring in:
  1. Cytochrome c oxidase subunit 7A1, mitochondrial
IPR000298
Domain description: Cytochrome c oxidase subunit III-like
Occurring in:
  1. Cytochrome c oxidase subunit 3
IPR034210
Domain description: Cytochrome c oxidase subunit 2, C-terminal
Occurring in:
  1. Cytochrome c oxidase subunit 2
IPR024791
Domain description: Cytochrome c oxidase subunit III
Occurring in:
  1. Cytochrome c oxidase subunit 3
IPR014222
Domain description: Cytochrome c oxidase, subunit II
Occurring in:
  1. Cytochrome c oxidase subunit 2
IPR033945
Domain description: Cytochrome c oxidase subunit III domain
Occurring in:
  1. Cytochrome c oxidase subunit 3
IPR035973
Domain description: Cytochrome c oxidase subunit III-like superfamily
Occurring in:
  1. Cytochrome c oxidase subunit 3
IPR034884
Domain description: Mitochondrial cytochrome c oxidase subunit VIc/VIIs
Occurring in:
  1. Cytochrome c oxidase subunit 6C
IPR002429
Domain description: Cytochrome c oxidase subunit II-like C-terminal
Occurring in:
  1. Cytochrome c oxidase subunit 2
IPR011759
Domain description: Cytochrome C oxidase subunit II, transmembrane domain
Occurring in:
  1. Cytochrome c oxidase subunit 2

Structure domains

CATH CATH domains
4.10.49.10
Class: Few Secondary Structures
Architecture: Irregular
Topology: Cytochrome C Oxidase; Chain L
Homology: Cytochrome c oxidase subunit VIIc
Occurring in:
  1. Cytochrome c oxidase subunit 7C, mitochondrial
1 copy of CATH domain 4.10.49.10 (Cytochrome C Oxidase; Chain L) in Cytochrome c oxidase subunit 7C, mitochondrial in PDB 2eim.
1.10.10.140
Class: Mainly Alpha
Architecture: Orthogonal Bundle
Topology: Arc Repressor Mutant, subunit A
Homology: Cytochrome c oxidase, subunit VIb
Occurring in:
  1. Cytochrome c oxidase subunit 6B1
1 copy of CATH domain 1.10.10.140 (Arc Repressor Mutant, subunit A) in Cytochrome c oxidase subunit 6B1 in PDB 2eim.
4.10.95.10
Class: Few Secondary Structures
Architecture: Irregular
Topology: Cytochrome C Oxidase; Chain G
Homology: Cytochrome c oxidase, subunit VIa
Occurring in:
  1. Cytochrome c oxidase subunit 6A2, mitochondrial
1 copy of CATH domain 4.10.95.10 (Cytochrome C Oxidase; Chain G) in Cytochrome c oxidase subunit 6A2, mitochondrial in PDB 2eim.
1.10.287.70
Class: Mainly Alpha
Architecture: Orthogonal Bundle
Topology: Helix Hairpins
Homology: Helix Hairpins
Occurring in:
  1. Cytochrome c oxidase subunit 3
1 copy of CATH domain 1.10.287.70 (Helix Hairpins) in Cytochrome c oxidase subunit 3 in PDB 2eim.
1.10.287.90
Class: Mainly Alpha
Architecture: Orthogonal Bundle
Topology: Helix Hairpins
Homology: Helix Hairpins
Occurring in:
  1. Cytochrome c oxidase subunit 2
1 copy of CATH domain 1.10.287.90 (Helix Hairpins) in Cytochrome c oxidase subunit 2 in PDB 2eim.
4.10.93.10
Class: Few Secondary Structures
Architecture: Irregular
Topology: Cytochrome C Oxidase; Chain I
Homology: Mitochondrial cytochrome c oxidase subunit VIc/VIIs
Occurring in:
  1. Cytochrome c oxidase subunit 6C
1 copy of CATH domain 4.10.93.10 (Cytochrome C Oxidase; Chain I) in Cytochrome c oxidase subunit 6C in PDB 2eim.
2.60.11.10
Class: Mainly Beta
Architecture: Sandwich
Topology: Cytochrome C Oxidase; Chain F
Homology: Cytochrome c oxidase, subunit Vb
Occurring in:
  1. Cytochrome c oxidase subunit 5B, mitochondrial
1 copy of CATH domain 2.60.11.10 (Cytochrome C Oxidase; Chain F) in Cytochrome c oxidase subunit 5B, mitochondrial in PDB 2eim.
2.60.40.420
Class: Mainly Beta
Architecture: Sandwich
Topology: Immunoglobulin-like
Homology: Cupredoxins - blue copper proteins
Occurring in:
  1. Cytochrome c oxidase subunit 2
1 copy of CATH domain 2.60.40.420 (Immunoglobulin-like) in Cytochrome c oxidase subunit 2 in PDB 2eim.
4.10.81.10
Class: Few Secondary Structures
Architecture: Irregular
Topology: Cytochrome C Oxidase; Chain M
Homology: Cytochrome c oxidase, subunit 8
Occurring in:
  1. Cytochrome c oxidase subunit 8B, mitochondrial
1 copy of CATH domain 4.10.81.10 (Cytochrome C Oxidase; Chain M) in Cytochrome c oxidase subunit 8B, mitochondrial in PDB 2eim.
1.20.210.10
Class: Mainly Alpha
Architecture: Up-down Bundle
Topology: Cytochrome C Oxidase; Chain A
Homology: Cytochrome c oxidase-like, subunit I domain
Occurring in:
  1. Cytochrome c oxidase subunit 1
1 copy of CATH domain 1.20.210.10 (Cytochrome C Oxidase; Chain A) in Cytochrome c oxidase subunit 1 in PDB 2eim.
1.20.120.80
Class: Mainly Alpha
Architecture: Up-down Bundle
Topology: Four Helix Bundle (Hemerythrin (Met), subunit A)
Homology: Cytochrome c oxidase, subunit III, four-helix bundle
Occurring in:
  1. Cytochrome c oxidase subunit 3
1 copy of CATH domain 1.20.120.80 (Four Helix Bundle (Hemerythrin (Met), subunit A)) in Cytochrome c oxidase subunit 3 in PDB 2eim.
4.10.51.10
Class: Few Secondary Structures
Architecture: Irregular
Topology: Cytochrome C Oxidase; Chain K
Homology: Cytochrome C Oxidase, chain K
Occurring in:
  1. Cytochrome c oxidase subunit 7B, mitochondrial
1 copy of CATH domain 4.10.51.10 (Cytochrome C Oxidase; Chain K) in Cytochrome c oxidase subunit 7B, mitochondrial in PDB 2eim.
1.25.40.40
Class: Mainly Alpha
Architecture: Alpha Horseshoe
Topology: Serine Threonine Protein Phosphatase 5, Tetratricopeptide repeat
Homology: Cytochrome c oxidase, subunit Va/VI
Occurring in:
  1. Cytochrome c oxidase subunit 5A, mitochondrial
1 copy of CATH domain 1.25.40.40 (Serine Threonine Protein Phosphatase 5, Tetratricopeptide repeat) in Cytochrome c oxidase subunit 5A, mitochondrial in PDB 2eim.
4.10.91.10
Class: Few Secondary Structures
Architecture: Irregular
Topology: Cytochrome C Oxidase; Chain J
Homology: Cytochrome c oxidase, subunit VIIa
Occurring in:
  1. Cytochrome c oxidase subunit 7A1, mitochondrial
1 copy of CATH domain 4.10.91.10 (Cytochrome C Oxidase; Chain J) in Cytochrome c oxidase subunit 7A1, mitochondrial in PDB 2eim.
1.10.442.10
Class: Mainly Alpha
Architecture: Orthogonal Bundle
Topology: Cytochrome C Oxidase; Chain D
Homology: Cytochrome c oxidase subunit IV
Occurring in:
  1. Cytochrome c oxidase subunit 4 isoform 1, mitochondrial
1 copy of CATH domain 1.10.442.10 (Cytochrome C Oxidase; Chain D) in Cytochrome c oxidase subunit 4 isoform 1, mitochondrial in PDB 2eim.
SCOP SCOP annotations
81405
Class: Membrane and cell surface proteins and peptides
Fold: Single transmembrane helix
Superfamily: Mitochondrial cytochrome c oxidase subunit IV
Occurring in:
  1. Cytochrome c oxidase subunit 4 isoform 1, mitochondrial
1 copy of SCOP domain 81405 (Mitochondrial cytochrome c oxidase subunit IV) in Cytochrome c oxidase subunit 4 isoform 1, mitochondrial in PDB 2eim.
57818
Class: Small proteins
Fold: Rubredoxin-like
Superfamily: Rubredoxin-like
Occurring in:
  1. Cytochrome c oxidase subunit 5B, mitochondrial
1 copy of SCOP domain 57818 (Cytochrome c oxidase Subunit F) in Cytochrome c oxidase subunit 5B, mitochondrial in PDB 2eim.
81463
Class: Membrane and cell surface proteins and peptides
Fold: Transmembrane helix hairpin
Superfamily: Cytochrome c oxidase subunit II-like, transmembrane region
Occurring in:
  1. Cytochrome c oxidase subunit 2
1 copy of SCOP domain 81463 (Cytochrome c oxidase subunit II-like, transmembrane region) in Cytochrome c oxidase subunit 2 in PDB 2eim.
81430
Class: Membrane and cell surface proteins and peptides
Fold: Single transmembrane helix
Superfamily: Mitochondrial cytochrome c oxidase subunit VIIIb (aka IX)
Occurring in:
  1. Cytochrome c oxidase subunit 8B, mitochondrial
1 copy of SCOP domain 81430 (Mitochondrial cytochrome c oxidase subunit VIIIb (aka IX)) in Cytochrome c oxidase subunit 8B, mitochondrial in PDB 2eim.
81426
Class: Membrane and cell surface proteins and peptides
Fold: Single transmembrane helix
Superfamily: Mitochondrial cytochrome c oxidase subunit VIIc (aka VIIIa)
Occurring in:
  1. Cytochrome c oxidase subunit 7C, mitochondrial
1 copy of SCOP domain 81426 (Mitochondrial cytochrome c oxidase subunit VIIc (aka VIIIa)) in Cytochrome c oxidase subunit 7C, mitochondrial in PDB 2eim.
47695
Class: All alpha proteins
Fold: Cytochrome c oxidase subunit h
Superfamily: Cytochrome c oxidase subunit h
Occurring in:
  1. Cytochrome c oxidase subunit 6B1
1 copy of SCOP domain 47695 (Cytochrome c oxidase subunit h) in Cytochrome c oxidase subunit 6B1 in PDB 2eim.
81422
Class: Membrane and cell surface proteins and peptides
Fold: Single transmembrane helix
Superfamily: Mitochondrial cytochrome c oxidase subunit VIIb
Occurring in:
  1. Cytochrome c oxidase subunit 7B, mitochondrial
1 copy of SCOP domain 81422 (Mitochondrial cytochrome c oxidase subunit VIIb) in Cytochrome c oxidase subunit 7B, mitochondrial in PDB 2eim.
81451
Class: Membrane and cell surface proteins and peptides
Fold: Cytochrome c oxidase subunit III-like
Superfamily: Cytochrome c oxidase subunit III-like
Occurring in:
  1. Cytochrome c oxidase subunit 3
1 copy of SCOP domain 81451 (Cytochrome c oxidase subunit III-like) in Cytochrome c oxidase subunit 3 in PDB 2eim.
81418
Class: Membrane and cell surface proteins and peptides
Fold: Single transmembrane helix
Superfamily: Mitochondrial cytochrome c oxidase subunit VIIa
Occurring in:
  1. Cytochrome c oxidase subunit 7A1, mitochondrial
1 copy of SCOP domain 81418 (Mitochondrial cytochrome c oxidase subunit VIIa) in Cytochrome c oxidase subunit 7A1, mitochondrial in PDB 2eim.
81414
Class: Membrane and cell surface proteins and peptides
Fold: Single transmembrane helix
Superfamily: Mitochondrial cytochrome c oxidase subunit VIc
Occurring in:
  1. Cytochrome c oxidase subunit 6C
1 copy of SCOP domain 81414 (Mitochondrial cytochrome c oxidase subunit VIc) in Cytochrome c oxidase subunit 6C in PDB 2eim.
49541
Class: All beta proteins
Fold: Cupredoxin-like
Superfamily: Cupredoxins
Occurring in:
  1. Cytochrome c oxidase subunit 2
1 copy of SCOP domain 49541 (Periplasmic domain of cytochrome c oxidase subunit II) in Cytochrome c oxidase subunit 2 in PDB 2eim.
81410
Class: Membrane and cell surface proteins and peptides
Fold: Single transmembrane helix
Superfamily: Mitochondrial cytochrome c oxidase subunit VIa
Occurring in:
  1. Cytochrome c oxidase subunit 6A2, mitochondrial
1 copy of SCOP domain 81410 (Mitochondrial cytochrome c oxidase subunit VIa) in Cytochrome c oxidase subunit 6A2, mitochondrial in PDB 2eim.
81441
Class: Membrane and cell surface proteins and peptides
Fold: Cytochrome c oxidase subunit I-like
Superfamily: Cytochrome c oxidase subunit I-like
Occurring in:
  1. Cytochrome c oxidase subunit 1
1 copy of SCOP domain 81441 (Cytochrome c oxidase subunit I-like) in Cytochrome c oxidase subunit 1 in PDB 2eim.
48480
Class: All alpha proteins
Fold: alpha-alpha superhelix
Superfamily: Cytochrome c oxidase subunit E
Occurring in:
  1. Cytochrome c oxidase subunit 5A, mitochondrial
1 copy of SCOP domain 48480 (Cytochrome c oxidase subunit E) in Cytochrome c oxidase subunit 5A, mitochondrial in PDB 2eim.