Reviewed, UniProtKB/Swiss-Prot P00171 (CYB5_BOVIN)

Names and origin

Protein names

Recommended name:
    Cytochrome b5

Gene names

Name:	CYB5A
Synonyms:	CYB5

Organism

Bos taurus (Bovine)

Taxonomic identifier

9913 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Laurasiatheria › Cetartiodactyla › Ruminantia › Pecora › Bovidae › Bovinae › Bos

Protein attributes

Sequence length	134 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	Cytochrome b5 is a membrane bound hemoprotein which function as an electron carrier for several membrane bound oxygenases.
Subcellular location	Endoplasmic reticulum membrane; Single-pass membrane protein; Cytoplasmic side. Microsome membrane; Single-pass membrane protein; Cytoplasmic side.
Sequence similarities	Belongs to the cytochrome b5 family. Contains 1 cytochrome b5 heme-binding domain.

Ontologies

Keywords
Biological process	Electron transport Transport
Cellular component	Endoplasmic reticulum Membrane Microsome
Domain	Transmembrane
Ligand	Heme Iron Metal-binding
PTM	Acetylation
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Biological process	electron transport chain Inferred from electronic annotation. Source: UniProtKB-KW transport Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	endoplasmic reticulum membrane Inferred from electronic annotation. Source: UniProtKB-SubCell integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW microsome Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	heme 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.4 Ref.5 Ref.6

Chain

2 – 134

133

Cytochrome b5

PRO_0000166008

Regions

Transmembrane

109 – 131

23

Potential

Domain

9 – 85

77

Cytochrome b5 heme-binding

Sites

Metal binding

44

1

Iron (heme axial ligand) Ref.12

Metal binding

68

1

Iron (heme axial ligand) Ref.12

Amino acid modifications

Modified residue

2

1

N-acetylalanine Ref.4 Ref.6

Modified residue

19

1

N6-acetyllysine By similarity

Experimental info

Sequence conflict

2 – 5

4

AEES → ZSZZBA AA sequence Ref.5

Sequence conflict

16 – 18

3

EIQ → QIE AA sequence Ref.7

Sequence conflict

18

1

Q → E AA sequence Ref.8

Sequence conflict

62

1

N → D AA sequence Ref.7

Sequence conflict

62

1

N → D AA sequence Ref.8

Sequence conflict

98

1

S → SES Ref.2

Sequence conflict

134

1

N → D AA sequence Ref.5

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

134

Helix Strand Turn

Details...

Helix

14 – 17

4

Beta strand

25 – 30

6

Beta strand

33 – 36

4

Turn

38 – 43

6

Helix

49 – 54

6

Helix

60 – 65

6

Helix

70 – 76

7

Turn

77 – 79

3

Beta strand

80 – 84

5

Helix

86 – 91

6

Sequences

	Sequence		Length	Mass (Da)
	P00171-1 [UniParc]. Last modified January 23, 2007. Version 3. Checksum: 7B7B605158D97525	FASTA	134	15,329
	10 20 30 40 50 60 MAEESSKAVK YYTLEEIQKH NNSKSTWLIL HYKVYDLTKF LEEHPGGEEV LREQAGGDAT 70 80 90 100 110 120 ENFEDVGHST DARELSKTFI IGELHPDDRS KITKPSESII TTIDSNPSWW TNWLIPAISA 130 LFVALIYHLY TSEN

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"The complete nucleotide sequence of bovine liver cytochrome b5 mRNA." Cristiano R.J., Steggles A.W. Nucleic Acids Res. 17:799-799(1989) [PubMed: 2915932] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"The isolation and characterization of the bovine cytochrome b5 gene, and a transcribed pseudogene." Cristiano R.J., Giordano S.J., Steggles A.W. Genomics 17:348-354(1993) [PubMed: 8406485] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Tissue: Liver.
[3]	NIH - Mammalian Gene Collection (MGC) project Submitted (OCT-2005) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Strain: Hereford. Tissue: Fetal liver.
[4]	"Amino acid sequences of cytochrome b5 from human, porcine, and bovine erythrocytes and comparison with liver microsomal cytochrome b5." Abe K., Kimura S., Kizawa R., Anan F.K., Sugita Y. J. Biochem. 97:1659-1668(1985) [PubMed: 4030743] [Abstract] Cited for: PROTEIN SEQUENCE OF 2-98. Tissue: Erythrocyte.
[5]	"Cytochrome b5 from microsomal membranes of equine, bovine, and porcine livers. Isolation and properties of preparations containing the membranous segment." Ozols J. Biochemistry 13:426-434(1974) [PubMed: 4810060] [Abstract] Cited for: PROTEIN SEQUENCE OF 2-11 AND 131-134.
[6]	"Structure of cytochrome b5 and its topology in the microsomal membrane." Ozols J. Biochim. Biophys. Acta 997:121-130(1989) [PubMed: 2752049] [Abstract] Cited for: PROTEIN SEQUENCE OF 2-6 AND 15-18.
[7]	"Correction of the amino acid sequence of calf liver microsomal cytochrome b5." Ozols J., Strittmatter P. J. Biol. Chem. 244:6617-6618(1969) [PubMed: 5391285] [Abstract] Cited for: PROTEIN SEQUENCE OF 6-98.
[8]	"Comparative study of the primary structures of cytochrome b5 from four species." Tsugita A., Kobayashi M., Tani S., Kyo S., Rashid M.A., Yoshida Y., Kajihara T., Hagihara B. Proc. Natl. Acad. Sci. U.S.A. 67:442-447(1970) [PubMed: 5272324] [Abstract] Cited for: PROTEIN SEQUENCE OF 6-96.
[9]	"The primary structure of the nonpolar segment of bovine cytochrome b5." Fleming P.J., Dailey H.A., Corcoran D., Strittmatter P. J. Biol. Chem. 253:5369-5372(1978) [PubMed: 670203] [Abstract] Cited for: PROTEIN SEQUENCE OF 92-134.
[10]	"The structure of cytochrome b-5 at 2.0-A resolution." Mathews F.S., Argos P., Levine M. Cold Spring Harb. Symp. Quant. Biol. 37:387-395(1971) Cited for: X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF OXIDIZED FORM.
[11]	"The structure of ferrocytochrome b5 at 2.8-A resolution." Argos P., Mathews F.S. J. Biol. Chem. 250:747-751(1975) [PubMed: 1167544] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.8 ANGSTROMS) OF REDUCED FORM.
[12]	"Refinement and structural analysis of bovine cytochrome b5 at 1.5-A resolution." Durley R.C.E., Mathews F.S. Acta Crystallogr. D 52:65-76(1996) [PubMed: 15299727] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.5 ANGSTROMS).
[13]	"Crystal structure of recombinant trypsin-solubilized fragment of cytochrome b5 and the structural comparison with Val61His mutant." Wu J., Gan J.-H., Xia Z.-X., Wang Y.-H., Wang W.-H., Xue L.-L., Xie Y., Huang Z.-X. Proteins 40:249-257(2000) [PubMed: 10842340] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.9 ANGSTROMS) OF 8-89, MUTAGENESIS.
[14]	"Structures of V45E and V45Y mutants and structure comparison of a variety of cytochrome b5 mutants." Gan J.-H., Wu J., Wang Z.-Q., Wang Y.-H., Huang Z.-X., Xia Z.-X. Acta Crystallogr. D 58:1298-1306(2002) [PubMed: 12136141] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.8 ANGSTROMS) OF 8-89, MUTAGENESIS.
[15]	"X-ray crystallography, CD and kinetic studies revealed the essence of the abnormal behaviors of the cytochrome b5 Phe35->Tyr mutant." Yao P., Wu J., Wang Y.-H., Sun B.-Y., Xia Z.-X., Huang Z.-X. Eur. J. Biochem. 269:4287-4296(2002) [PubMed: 12199707] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.8 ANGSTROMS) OF 8-89, CIRCULAR DICHROISM ANALYSIS, MUTAGENESIS.
[16]	"The solution structure of bovine ferricytochrome b5 determined using heteronuclear NMR methods." Muskett F.W., Kelly G.P., Whitford D. J. Mol. Biol. 258:172-189(1996) [PubMed: 8613986] [Abstract] Cited for: STRUCTURE BY NMR.
[17]	"Solution structure of cytochrome b5 mutant (E44/48/56A/D60A) and its interaction with cytochrome c." Wu Y., Wang Y., Qian C., Lu J., Li E., Wang W., Lu J., Xie Y., Wang J., Zhu D., Huang Z., Tang W. Eur. J. Biochem. 268:1620-1630(2001) [PubMed: 11248680] [Abstract] Cited for: STRUCTURE BY NMR OF 8-89, MUTAGENESIS.
[18]	"Effects of charged amino-acid mutation on the solution structure of cytochrome b5 and binding between cytochrome b5 and cytochrome c." Qian C., Yao Y., Ye K., Wang J., Tang W., Wang Y., Wang W., Lu J., Xie Y., Huang Z. Protein Sci. 10:2451-2459(2001) [PubMed: 11714912] [Abstract] Cited for: STRUCTURE BY NMR OF 8-89, MUTAGENESIS.
[19]	"The solution structure of the oxidized bovine microsomal cytochrome b5 mutant V61H." Cao C., Zhang Q., Xue L.-L., Ma J., Wang Y.-H., Wu H., Huang Z.-X. Biochem. Biophys. Res. Commun. 307:600-609(2003) [PubMed: 12893266] [Abstract] Cited for: STRUCTURE BY NMR OF 8-89, MUTAGENESIS.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBLGenBankDDBJ

X13617 mRNA. Translation: CAA31949.1.
M63328, M63326, M63327 Genomic DNA. Translation: AAC14455.1. Sequence problems.
L22966 Genomic DNA. No translation available.
BC108113 mRNA. Translation: AAI08114.1.

IPI

IPI00714055.

PIR

CBBO5. A47215.

RefSeq

NP_776458.1.

UniGene

Bt.64615

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1CYO	X-ray	1.50	A	6-98	[»]
1EHB	X-ray	1.90	A	8-89	[»]
1ES1	X-ray	2.10	A	8-89	[»]
1F03	NMR	-	A	8-89	[»]
1F04	NMR	-	A	8-89	[»]
1HKO	NMR	-	A	2-105	[»]
1I5U	NMR	-	A	8-89	[»]
1J0Q	NMR	-	A	8-89	[»]
1LQX	X-ray	1.80	A	8-89	[»]
1LR6	X-ray	1.90	A	8-89	[»]
1M20	X-ray	1.80	A	8-89	[»]
1M2I	X-ray	1.80	A	8-89	[»]
1M2M	X-ray	1.80	A	8-89	[»]
1M59	X-ray	1.90	A	8-89	[»]
1NX7	NMR	-	A	8-88	[»]
1SH4	NMR	-	A	8-88	[»]
1U9M	X-ray	2.00	A/B/C/D/E/F	8-88	[»]
1U9U	X-ray	1.86	A	8-88	[»]

ModBase

Search...

Genome annotation databases

Ensembl

ENSBTAG00000012012. Bos taurus. [Contig view]

GeneID

281110.

KEGG

bta:281110.

Phylogenomic databases

HOVERGEN

P00171.

OMA

P00171. QKHNHSK.

Family and domain databases

InterPro

IPR001199. Cyt_B5.
IPR018506. Cyt_B5_heme-BS.
[Graphical view]

Gene3D

G3DSA:3.10.120.10. Cyt_B5. 1 hit.

Pfam

PF00173. Cyt-b5. 1 hit.
[Graphical view]

PRINTS

PR00363. CYTOCHROMEB5.

ProDom

PD000612. Cyt_B5. 1 hit.
[Graphical view] [Entries sharing at least one domain]

PROSITE

PS00191. CYTOCHROME_B5_1. 1 hit.
PS50255. CYTOCHROME_B5_2. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

CYB5_BOVIN

Accession

Primary (citable) accession number: P00171
Secondary accession number(s): Q27947, Q28837, Q32PH5

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	January 23, 2007
Last modified:	June 16, 2009
This is version 100 of the entry and version 3 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HPI (Human Proteome Initiative)