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Details on Person UniProt:P00387-1 CYB5R3

Class:IdReferenceIsoform:402221
_chainChangeLoginitiator methionine:1 added on Fri February 6 2015;chain:2-301 added on Fri February 6 2015;chain:27-301 added on Fri February 6 2015;chain:27-301 for 402221 removed on Fri November 4 2022;initiator methionine:1 for 402221 removed on Fri Nov 03 2023;initiator methionine: for 402221 added on Fri Nov 03 2023;initiator methionine: for 402221 removed on Fri Aug 15 2025;initiator methionine:1 for 402221 added on Fri Aug 15 2025
_displayNameUniProt:P00387-1 CYB5R3
_timestamp2025-08-15 21:47:00
chaininitiator methionine:1
chain:2-301
checksumFDCDCDC4EC3570B4
commentFUNCTION Catalyzes the reduction of two molecules of cytochrome b5 using NADH as the electron donor.CATALYTIC ACTIVITY 2 Fe(III)-[cytochrome b5] + NADH = 2 Fe(II)-[cytochrome b5] + NAD(+) + H(+)CATALYTIC ACTIVITY 2 Fe(III)-[cytochrome b5] + NADH = 2 Fe(II)-[cytochrome b5] + NAD(+) + H(+)COFACTOR kcat is 896 sec(-1).SUBUNIT Component of a complex composed of cytochrome b5, NADH-cytochrome b5 reductase (CYB5R3) and MTARC2 (By similarity). Interacts with MTLN; the interaction is required to maintain cellular lipid composition and leads to stimulation of mitochondrial respiratory complex I activity (By similarity).INTERACTION Expressed at late stages of erythroid maturation.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.DISEASE The disease is caused by variants affecting the gene represented in this entry.SIMILARITY Belongs to the flavoprotein pyridine nucleotide cytochrome reductase family.
created[InstanceEdit:400710] Schmidt, EE, 2009-03-25 05:33:35
descriptionrecommendedName: fullName evidence="28"NADH-cytochrome b5 reductase 3 shortName: B5R shortName: Cytochrome b5 reductase ecNumber evidence="5 7 10 12 13 19 21"1.6.2.2 alternativeName: fullName evidence="27"Diaphorase-1
geneNameCYB5R3
DIA1
identifierP00387
isoformParent
isSequenceChangedFALSE
keyword3D-structure
Acetylation
Alternative promoter usage
Alternative splicing
Cholesterol biosynthesis
Cholesterol metabolism
Cytoplasm
Direct protein sequencing
Disease variant
Endoplasmic reticulum
FAD
Flavoprotein
Lipid biosynthesis
Lipid metabolism
Lipoprotein
Membrane
Mitochondrion
Mitochondrion outer membrane
Myristate
NAD
Oxidoreductase
Phosphoprotein
Proteomics identification
Reference proteome
Steroid biosynthesis
Steroid metabolism
Sterol biosynthesis
Sterol metabolism
modified[InstanceEdit:9836292] Weiser, Joel, 2023-05-25
[InstanceEdit:9852000] Weiser, Joel, 2023-11-03
[InstanceEdit:9926675] Weiser, Joel, 2024-11-03
[InstanceEdit:9939033] Weiser, Joel, 2025-02-21
[InstanceEdit:9963647] Weiser, Joel, 2025-08-15
nameCYB5R3
referenceDatabase[ReferenceDatabase:2] UniProt
referenceGene[ReferenceDNASequence:9003089] ENSEMBL:ENSG00000100243 CYB5R3 [Homo sapiens]
secondaryIdentifierNB5R3_HUMAN
B1AHF2
B7Z7L3
O75675
Q8TDL8
Q8WTS8
Q9UEN4
Q9UEN5
Q9UL55
Q9UL56
sequenceLength301
species[Species:48887] Homo sapiens
variantIdentifierP00387-1
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No pathways have been reviewed or authored by UniProt:P00387-1 CYB5R3 (402221)