Gene/Proteome Database (LMPD)

LMPD ID
LMP006716
Gene ID
1727
Species
Homo sapiens (Human)
Gene Name
cytochrome b5 reductase 3
Gene Symbol
CYB5R3
Synonyms
B5R; DIA1
Alternate Names
NADH-cytochrome b5 reductase 3; diaphorase-1; NADH-cytochrome b5 reductase 3 soluble form; NADH-cytochrome b5 reductase 3 membrane-bound form
Chromosome
22
Map Location
22q13.2
EC Number
1.6.2.2
Summary
This gene encodes cytochrome b5 reductase, which includes a membrane-bound form in somatic cells (anchored in the endoplasmic reticulum, mitochondrial and other membranes) and a soluble form in erythrocytes. The membrane-bound form exists mainly on the cytoplasmic side of the endoplasmic reticulum and functions in desaturation and elongation of fatty acids, in cholesterol biosynthesis, and in drug metabolism. The erythrocyte form is located in a soluble fraction of circulating erythrocytes and is involved in methemoglobin reduction. The membrane-bound form has both membrane-binding and catalytic domains, while the soluble form has only the catalytic domain. Alternate splicing results in multiple transcript variants. Mutations in this gene cause methemoglobinemias. [provided by RefSeq, Jan 2010]
Orthologs
View orthologs and multiple alignments for CYB5R3

Proteins

NADH-cytochrome b5 reductase 3 isoform 1
Refseq ID NP_000389
Protein GI 4503327
UniProt ID P00387
mRNA ID NM_000398
Length 301
RefSeq Status REVIEWED
MGAQLSTLGHMVLFPVWFLYSLLMKLFQRSTPAITLESPDIKYPLRLIDREIISHDTRRFRFALPSPQHILGLPVGQHIYLSARIDGNLVVRPYTPISSDDDKGFVDLVIKVYFKDTHPKFPAGGKMSQYLESMQIGDTIEFRGPSGLLVYQGKGKFAIRPDKKSNPIIRTVKSVGMIAGGTGITPMLQVIRAIMKDPDDHTVCHLLFANQTEKDILLRPELEELRNKHSARFKLWYTLDRAPEAWDYGQGFVNEEMIRDHLPPPEEEPLVLMCGPPPMIQYACLPNLDHVGHPTERCFVF
NADH-cytochrome b5 reductase 3 isoform 2
Refseq ID NP_001123291
Protein GI 193794826
UniProt ID P00387
mRNA ID NM_001129819
Length 278
RefSeq Status REVIEWED
MKLFQRSTPAITLESPDIKYPLRLIDREIISHDTRRFRFALPSPQHILGLPVGQHIYLSARIDGNLVVRPYTPISSDDDKGFVDLVIKVYFKDTHPKFPAGGKMSQYLESMQIGDTIEFRGPSGLLVYQGKGKFAIRPDKKSNPIIRTVKSVGMIAGGTGITPMLQVIRAIMKDPDDHTVCHLLFANQTEKDILLRPELEELRNKHSARFKLWYTLDRAPEAWDYGQGFVNEEMIRDHLPPPEEEPLVLMCGPPPMIQYACLPNLDHVGHPTERCFVF
NADH-cytochrome b5 reductase 3 isoform 2
Refseq ID NP_015565
Protein GI 6552328
UniProt ID P00387
mRNA ID NM_007326
Length 278
RefSeq Status REVIEWED
Protein sequence is identical to GI:193794826 (mRNA isoform)
mat_peptide: 27..301 product: NADH-cytochrome b5 reductase 3 soluble form experiment: experimental evidence, no additional details recorded note: propagated from UniProtKB/Swiss-Prot (P00387.3) calculated_mol_wt: 31256 peptide sequence: FQRSTPAITLESPDIKYPLRLIDREIISHDTRRFRFALPSPQHILGLPVGQHIYLSARIDGNLVVRPYTPISSDDDKGFVDLVIKVYFKDTHPKFPAGGKMSQYLESMQIGDTIEFRGPSGLLVYQGKGKFAIRPDKKSNPIIRTVKSVGMIAGGTGITPMLQVIRAIMKDPDDHTVCHLLFANQTEKDILLRPELEELRNKHSARFKLWYTLDRAPEAWDYGQGFVNEEMIRDHLPPPEEEPLVLMCGPPPMIQYACLPNLDHVGHPTERCFVF
NADH-cytochrome b5 reductase 3 isoform 3
Refseq ID NP_001165131
Protein GI 284448551
UniProt ID P00387
mRNA ID NM_001171660
Length 334
RefSeq Status REVIEWED
MNRSLLVGCMQSKDIWGREESICERLKQDGLDVERAESWELGHMVLFPVWFLYSLLMKLFQRSTPAITLESPDIKYPLRLIDREIISHDTRRFRFALPSPQHILGLPVGQHIYLSARIDGNLVVRPYTPISSDDDKGFVDLVIKVYFKDTHPKFPAGGKMSQYLESMQIGDTIEFRGPSGLLVYQGKGKFAIRPDKKSNPIIRTVKSVGMIAGGTGITPMLQVIRAIMKDPDDHTVCHLLFANQTEKDILLRPELEELRNKHSARFKLWYTLDRAPEAWDYGQGFVNEEMIRDHLPPPEEEPLVLMCGPPPMIQYACLPNLDHVGHPTERCFVF

Gene Information

Entrez Gene ID
1727
Gene Name
cytochrome b5 reductase 3
Gene Symbol
CYB5R3
Species
Homo sapiens

Gene Ontology (GO Annotations)

GO ID Source Type Description
GO:0005737 TAS:ProtInc C cytoplasm
GO:0005783 IDA:HPA C endoplasmic reticulum
GO:0005789 IEA:Ensembl C endoplasmic reticulum membrane
GO:0070062 IDA:UniProt C extracellular vesicular exosome
GO:0005833 TAS:ProtInc C hemoglobin complex
GO:0005811 IDA:UniProtKB C lipid particle
GO:0016020 IDA:UniProtKB C membrane
GO:0005743 IEA:Ensembl C mitochondrial inner membrane
GO:0005741 TAS:Reactome C mitochondrial outer membrane
GO:0005739 IDA:UniProt C mitochondrion
GO:0043531 IEA:Ensembl F ADP binding
GO:0016208 IEA:Ensembl F AMP binding
GO:0071949 IDA:UniProtKB F FAD binding
GO:0051287 IEA:Ensembl F NAD binding
GO:0004128 TAS:Reactome F cytochrome-b5 reductase activity, acting on NAD(P)H
GO:0050660 IEA:Ensembl F flavin adenine dinucleotide binding
GO:0019852 TAS:Reactome P L-ascorbic acid metabolic process
GO:0008015 TAS:ProtInc P blood circulation
GO:0006695 IEA:UniProtKB-KW P cholesterol biosynthetic process
GO:0044281 TAS:Reactome P small molecule metabolic process
GO:0006766 TAS:Reactome P vitamin metabolic process
GO:0006767 TAS:Reactome P water-soluble vitamin metabolic process

KEGG Pathway Links

KEGG Pathway ID Description
hsa00520 Amino sugar and nucleotide sugar metabolism

REACTOME Pathway Links

REACTOME Pathway ID Description
REACT_11238 Metabolism of water-soluble vitamins and cofactors
REACT_11202 Vitamin C (ascorbate) metabolism

Domain Information

InterPro Annotations

Accession Description
IPR017927 Ferredoxin reductase-type FAD-binding domain
IPR001709 Flavoprotein pyridine nucleotide cytochrome reductase
IPR001834 NADH:cytochrome b5 reductase (CBR)
IPR001433 Oxidoreductase FAD/NAD(P)-binding
IPR008333 Oxidoreductase, FAD-binding domain
IPR017938 Riboflavin synthase-like beta-barrel

UniProt Annotations

Entry Information

Gene Name
cytochrome b5 reductase 3
Protein Entry
NB5R3_HUMAN
UniProt ID
P00387
Species
Human

Comments

Comment Type Description
Alternative Products Event=Alternative promoter usage, Alternative splicing; Named isoforms=3; Name=1; Synonyms=M; IsoId=P00387-1; Sequence=Displayed; Name=2; Synonyms=S; IsoId=P00387-2; Sequence=VSP_010200; Name=3; IsoId=P00387-3; Sequence=VSP_042827; Note=No experimental confirmation available.;
Catalytic Activity NADH + 2 ferricytochrome b5 = NAD(+) + H(+) + 2 ferrocytochrome b5.
Cofactor Name=FAD; Xref=ChEBI
Disease Methemoglobinemia CYB5R3-related (METHB-CYB5R3) [MIM
Function Desaturation and elongation of fatty acids, cholesterol biosynthesis, drug metabolism, and, in erythrocyte, methemoglobin reduction.
Polymorphism Ser-117 seems to only be found in persons of African origin. The allele frequency is 0.23 in African Americans. It was not found in Caucasians, Asians, Indo-Aryans, or Arabs. There seems to be no effect on the enzyme activity.
Similarity Belongs to the flavoprotein pyridine nucleotide cytochrome reductase family.
Similarity Contains 1 FAD-binding FR-type domain.
Subcellular Location Isoform 1: Endoplasmic reticulum membrane; Lipid-anchor; Cytoplasmic side. Mitochondrion outer membrane; Lipid-anchor; Cytoplasmic side.
Subcellular Location Isoform 2: Cytoplasm. Note=Produces the soluble form found in erythrocytes.
Subunit Component of a complex composed of cytochrome b5, NADH- cytochrome b5 reductase (CYB5R3) and MOSC2.
Tissue Specificity Isoform 2 is expressed at late stages of erythroid maturation.
Web Resource Name=NIEHS-SNPs; URL="http://egp.gs.washington.edu/data/dia1/";

Identical and Related Proteins

Unique RefSeq proteins for LMP006716 (as displayed in Record Overview)

Protein GI Database Accession Length Protein Name
4503327 RefSeq NP_000389 301 NADH-cytochrome b5 reductase 3 isoform 1
193794826 RefSeq NP_001123291 278 NADH-cytochrome b5 reductase 3 isoform 2
284448551 RefSeq NP_001165131 334 NADH-cytochrome b5 reductase 3 isoform 3

Identical Sequences to LMP006716 proteins

Reference Database Accession Length Protein Name
GI:4503327 DBBJ BAG72513.1 301 cytochrome b5 reductase 3, partial [synthetic construct]
GI:284448551 DBBJ BAH13649.1 334 unnamed protein product [Homo sapiens]
GI:4503327 EMBL CAK54426.1 301 CYB5R3 [synthetic construct]
GI:4503327 EMBL CAK54725.1 301 CYB5R3, partial [synthetic construct]
GI:4503327 EMBL CBX85080.1 301 unnamed protein product [Homo sapiens]
GI:193794826 EMBL CBX85085.1 278 unnamed protein product [Homo sapiens]
GI:4503327 EMBL CBX85181.1 301 unnamed protein product [Homo sapiens]
GI:4503327 GenBank EAW73271.1 301 cytochrome b5 reductase 3, isoform CRA_d [Homo sapiens]
GI:193794826 RefSeq NP_015565.1 278 NADH-cytochrome b5 reductase 3 isoform 2 [Homo sapiens]
GI:193794826 RefSeq NP_001165132.1 278 NADH-cytochrome b5 reductase 3 isoform 2 [Homo sapiens]

Related Sequences to LMP006716 proteins

Reference Database Accession Length Protein Name
GI:284448551 DBBJ BAG72513.1 301 cytochrome b5 reductase 3, partial [synthetic construct]
GI:193794826 DBBJ BAG72513.1 301 cytochrome b5 reductase 3, partial [synthetic construct]
GI:4503327 DBBJ BAH13649.1 334 unnamed protein product [Homo sapiens]
GI:193794826 EMBL CAG30321.1 301 DIA1 [Homo sapiens]
GI:4503327 GenBank AAA59900.1 301 NADH-cytochrome b5 reductase [Homo sapiens]
GI:193794826 GenBank AAH04821.1 301 Cytochrome b5 reductase 3 [Homo sapiens]
GI:284448551 GenBank AAH04821.1 301 Cytochrome b5 reductase 3 [Homo sapiens]
GI:4503327 GenBank AAL87744.1 301 NADH-cytochrome b5 reductase [Homo sapiens]
GI:193794826 GenBank AAX32042.1 301 diaphorase [synthetic construct]
GI:193794826 GenBank AAX32043.1 301 diaphorase [synthetic construct]
GI:193794826 GenBank AAX32044.1 301 diaphorase [synthetic construct]
GI:4503327 GenBank EAW73270.1 315 cytochrome b5 reductase 3, isoform CRA_c [Homo sapiens]
GI:284448551 GenBank JAA32735.1 334 cytochrome b5 reductase 3 [Pan troglodytes]
GI:284448551 RefSeq NP_000389.1 301 NADH-cytochrome b5 reductase 3 isoform 1 [Homo sapiens]
GI:4503327 RefSeq NP_001165131.1 334 NADH-cytochrome b5 reductase 3 isoform 3 [Homo sapiens]
GI:284448551 RefSeq XP_003805223.1 334 PREDICTED: NADH-cytochrome b5 reductase 3 isoform X1 [Pan paniscus]
GI:4503327 RefSeq XP_004063628.1 301 PREDICTED: NADH-cytochrome b5 reductase 3-like isoform 1 [Gorilla gorilla gorilla]
GI:284448551 RefSeq XP_004063630.1 334 PREDICTED: NADH-cytochrome b5 reductase 3-like isoform 3 [Gorilla gorilla gorilla]