P00004 (CYC_HORSE) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Cytochrome c

Gene names

Name:	CYCS
Synonyms:	CYC

Organism

Equus caballus (Horse) [Reference proteome]

Taxonomic identifier

9796 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Laurasiatheria › Perissodactyla › Equidae › Equus › Equus

Protein attributes

Sequence length	105 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Electron carrier protein. The oxidized form of the cytochrome c heme group can accept an electron from the heme group of the cytochrome c1 subunit of cytochrome reductase. Cytochrome c then transfers this electron to the cytochrome oxidase complex, the final protein carrier in the mitochondrial electron-transport chain. Plays a role in apoptosis. Suppression of the anti-apoptotic members or activation of the pro-apoptotic members of the Bcl-2 family leads to altered mitochondrial membrane permeability resulting in release of cytochrome c into the cytosol. Binding of cytochrome c to Apaf-1 triggers the activation of caspase-9, which then accelerates apoptosis by activating other caspases By similarity.
Subcellular location	Mitochondrion intermembrane space. Note: Loosely associated with the inner membrane.
Post-translational modification	Binds 1 heme group per subunit. Phosphorylation at Tyr-49 and Tyr-98 both reduce by half the turnover in the reaction with cytochrome c oxidase, down-regulating mitochondrial respiration By similarity.
Miscellaneous	Mules and hinnies are heterozygous, having equal amount of horse and donkey cytochromes c.
Sequence similarities	Belongs to the cytochrome c family.

Ontologies

Keywords
Biological process	Apoptosis Electron transport Respiratory chain Transport
Cellular component	Mitochondrion
Ligand	Heme Iron Metal-binding
PTM	Acetylation Phosphoprotein
Technical term	3D-structure Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological_process	apoptotic DNA fragmentation Inferred from sequence or structural similarity. Source: UniProtKB electron transport chain Inferred from electronic annotation. Source: UniProtKB-KW
Cellular_component	cytosol Inferred from sequence or structural similarity. Source: UniProtKB mitochondrial intermembrane space Inferred from electronic annotation. Source: UniProtKB-SubCell respiratory chain Inferred from electronic annotation. Source: UniProtKB-KW
Molecular_function	electron transporter, transferring electrons from CoQH2-cytochrome c reductase complex and cytochrome c oxidase complex activity Inferred from sequence or structural similarity. Source: UniProtKB heme binding Inferred from electronic annotation. Source: InterPro iron ion binding Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Initiator methionine

1

1

Removed Ref.1

Chain

2 – 105

104

Cytochrome c

PRO_0000108217

Sites

Metal binding

19

1

Iron (heme axial ligand) Ref.2

Metal binding

81

1

Iron (heme axial ligand)

Binding site

15

1

Heme (covalent)

Binding site

18

1

Heme (covalent)

Amino acid modifications

Modified residue

2

1

N-acetylglycine Ref.1

Modified residue

49

1

Phosphotyrosine By similarity

Modified residue

98

1

Phosphotyrosine By similarity

Secondary structure

1

.

.

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.

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.

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105

Helix Strand Turn

Details...

Helix

4 – 14

11

Turn

15 – 18

4

Beta strand

21 – 24

4

Beta strand

28 – 30

3

Turn

34 – 37

4

Beta strand

39 – 42

4

Beta strand

44 – 47

4

Helix

51 – 54

4

Helix

62 – 70

9

Helix

72 – 75

4

Beta strand

76 – 78

3

Beta strand

86 – 88

3

Helix

89 – 102

14

Sequences

	Sequence		Length	Mass (Da)
	P00004 [UniParc]. Last modified January 23, 2007. Version 2. Checksum: 659BA128E53C3868	FASTA	105	11,833
	10 20 30 40 50 60 MGDVEKGKKI FVQKCAQCHT VEKGGKHKTG PNLHGLFGRK TGQAPGFTYT DANKNKGITW 70 80 90 100 KEETLMEYLE NPKKYIPGTK MIFAGIKKKT EREDLIAYLK KATNE

References

[1]	"Amino-acid sequence of horse heart cytochrome c." Margoliash E., Smith E.L., Kreil G., Tuppy H. Nature 192:1125-1127(1961) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 2-105, ACETYLATION AT GLY-2. Tissue: Heart.
[2]	"Ferricytochrome c. I. General features of the horse and bonito proteins at 2.8-A resolution." Dickerson R.E., Takano T., Eisenberg D., Kallai O.B., Samson L., Cooper A., Margoliash E. J. Biol. Chem. 246:1511-1535(1971) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.8 ANGSTROMS).
[3]	"High-resolution three-dimensional structure of horse heart cytochrome c." Bushnell G.W., Louie G.V., Brayer G.D. J. Mol. Biol. 214:585-595(1990) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.9 ANGSTROMS).
[4]	"The low ionic strength crystal structure of horse cytochrome c at 2.1-A resolution and comparison with its high ionic strength counterpart." Sanishvili R., Volz K.W., Westbrook E.M., Margoliash E. Structure 3:707-716(1995) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS).
[5]	"Proton resonance assignments of horse ferricytochrome c." Feng Y., Roder H., Englander S.W., Wand A.J., di Stefano D.L. Biochemistry 28:195-203(1989) [PubMed] [Europe PMC] [Abstract] Cited for: STRUCTURE BY NMR.
[6]	"Solution structure of horse heart ferricytochrome c and detection of redox-related structural changes by high-resolution 1H NMR." Qi P.X., Beckman R.A., Wand A.J. Biochemistry 35:12275-12286(1996) [PubMed] [Europe PMC] [Abstract] Cited for: STRUCTURE BY NMR.
[7]	"Solution structure of oxidized horse heart cytochrome c." Banci L., Bertini I., Gray H.B., Luchinat C., Reddig T., Rosato A., Turano P. Biochemistry 36:9867-9877(1997) [PubMed] [Europe PMC] [Abstract] Cited for: STRUCTURE BY NMR. Tissue: Heart.
+	Additional computationally mapped references.

Web resources

Protein Spotlight

Life shuttle - Issue 76 of November 2006

Cross-references

Sequence databases

PIR

CCHO. A00005.

UniGene

Eca.1571.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1AKK	NMR	-	A	2-105	[»]
1CRC	X-ray	2.08	A/B	2-105	[»]
1FI7	NMR	-	A	2-104	[»]
1FI9	NMR	-	A	2-104	[»]
1GIW	NMR	-	A	2-104	[»]
1HRC	X-ray	1.90	A	2-105	[»]
1I5T	NMR	-	A	2-104	[»]
1LC1	NMR	-	A	2-104	[»]
1LC2	NMR	-	A	2-104	[»]
1M60	NMR	-	A	2-104	[»]
1OCD	NMR	-	A	2-105	[»]
1U75	X-ray	2.55	B	2-104	[»]
1WEJ	X-ray	1.80	F	2-104	[»]
2FRC	NMR	-	A	2-105	[»]
2GIW	NMR	-	A	2-104	[»]
2PCB	X-ray	2.80	B	2-104	[»]
3NBS	X-ray	2.20	A/B/C/D	2-105	[»]
3NBT	X-ray	2.10	A/B/C/D/E/F	2-105	[»]
3O1Y	X-ray	1.75	A/B/C	2-105	[»]
3O20	X-ray	1.90	A/B/C	2-105	[»]

DisProt

DP00006.

ProteinModelPortal

P00004.

SMR

P00004. Positions 2-105.

ModBase

Search...

Protein-protein interaction databases

DIP

DIP-36774N.

IntAct

P00004. 2 interactions.

STRING

9796.ENSECAP00000012031.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Phylogenomic databases

eggNOG

COG3474.

HOGENOM

HOG000009762.

HOVERGEN

HBG003023.

InParanoid

P00004.

OrthoDB

EOG45DWQX.

Enzyme and pathway databases

SABIO-RK

P00004.

Family and domain databases

InterPro

IPR002327. Cyt_c_1A/1B.
IPR009056. Cyt_c_dom.
IPR003088. Cyt_c_I.
[Graphical view]

PANTHER

PTHR11961. PTHR11961. 1 hit.

Pfam

PF00034. Cytochrom_C. 1 hit.
[Graphical view]

PRINTS

PR00604. CYTCHRMECIAB.

SUPFAM

SSF46626. Cytochrome_c. 1 hit.

PROSITE

PS51007. CYTC. 1 hit.
[Graphical view]

ProtoNet

Search...

Other

EvolutionaryTrace

P00004.

PMAP-CutDB

P00004.

Entry information

Entry name

CYC_HORSE

Accession

Primary (citable) accession number: P00004

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	January 23, 2007
Last modified:	April 3, 2013
This is version 112 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program