P38626 (NCB5R_YEAST) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
NADH-cytochrome b5 reductase 1
EC=1.6.2.2

Alternative name(s):
Microsomal cytochrome b reductase
P35

Gene names

Name:	CBR1
Synonyms:	CBR, CBR5
Ordered Locus Names:	YIL043C

Organism

Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)

Taxonomic identifier

559292 [NCBI]

Taxonomic lineage

Eukaryota › Fungi › Dikarya › Ascomycota › Saccharomycotina › Saccharomycetes › Saccharomycetales › Saccharomycetaceae › Saccharomyces

Protein attributes

Sequence length	284 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Electron donor reductase for cytochrome b5. The cytochrome b5/NADH cytochrome b5 reductase electron transfer system supports the catalytic activity of several sterol biosynthetic enzymes. Plays a role in bud morphology. Ref.6
Catalytic activity	NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5.
Cofactor	FAD.
Enzyme regulation	Competitively inhibited by NAD+. Inhibited by mercurials such as p-chloromercuribenzoate (PCMB) and HgCl2. Enzymatic activity increases under anaerobic conditions. Ref.4 Ref.5
Subunit structure	Monomer. Interacts with STE20. Ref.4 Ref.12
Subcellular location	Endoplasmic reticulum membrane; Single-pass membrane protein. Mitochondrion outer membrane; Single-pass membrane protein Potential Ref.8 Ref.11.
Induction	Protein levels are highest during exponential growth phase and lowest in stationary phase. Ref.4 Ref.5
Miscellaneous	Present with 4820 molecules/cell in log phase SD medium. Ref.9
Sequence similarities	Belongs to the flavoprotein pyridine nucleotide cytochrome reductase family. Contains 1 FAD-binding FR-type domain.
Biophysicochemical properties	Kinetic parameters: KM=6.3 µM for NADH Ref.4 KM=0.8 µM for cytochrome b5 pH dependence: Optimum pH is 5.6. Active from pH 5 to 7.5.
Sequence caution	The sequence CAA82214.1 differs from that shown. Reason: Erroneous initiation. The sequence CAA86908.1 differs from that shown. Reason: Erroneous initiation.

Ontologies

Keywords
Cellular component	Endoplasmic reticulum Membrane Mitochondrion Mitochondrion outer membrane
Domain	Transmembrane Transmembrane helix
Ligand	FAD Flavoprotein NAD
Molecular function	Oxidoreductase
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
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 direct assay Ref.4. Source: SGD mitochondrial outer membrane Inferred from direct assay Ref.11. Source: SGD
Molecular function	cytochrome-b5 reductase activity Inferred from direct assay Ref.4. Source: SGD
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 284	284	NADH-cytochrome b5 reductase 1		PRO_0000167627
Regions
	Transmembrane	7 – 27	21	Helical; Potential
	Domain	38 – 142	105	FAD-binding FR-type
	Nucleotide binding	122 – 137	16	FAD By similarity
	Nucleotide binding	148 – 180	33	FAD By similarity

Sequences

	Sequence		Length	Mass (Da)
	P38626 [UniParc]. Last modified April 29, 2008. Version 2. Checksum: 0E71E7AB083BB623	FASTA	284	31,494
	10 20 30 40 50 60 MAIDAQKLVV VIVIVVVPLL FKFIIGPKTK PVLDPKRNDF QSFPLVEKTI LTHNTSMYKF 70 80 90 100 110 120 GLPHADDVLG LPIGQHIVIK ANINGKDITR SYTPTSLDGD TKGNFELLVK SYPTGNVSKM 130 140 150 160 170 180 IGELKIGDSI QIKGPRGNYH YERNCRSHLG MIAGGTGIAP MYQIMKAIAM DPHDTTKVSL 190 200 210 220 230 240 VFGNVHEEDI LLKKELEALV AMKPSQFKIV YYLDSPDRED WTGGVGYITK DVIKEHLPAA 250 260 270 280 TMDNVQILIC GPPAMVASVR RSTVDLGFRR SKPLSKMEDQ VFVF

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Isolation and complete sequence of CBR, a gene encoding a putative cytochrome b reductase in Saccharomyces cerevisiae." Csukai M., Murray M., Orr E. Eur. J. Biochem. 219:441-448(1994) [PubMed: 8307010] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: 842.
[2]	"The nucleotide sequence of Saccharomyces cerevisiae chromosome IX." Churcher C.M., Bowman S., Badcock K., Bankier A.T., Brown D., Chillingworth T., Connor R., Devlin K., Gentles S., Hamlin N., Harris D.E., Horsnell T., Hunt S., Jagels K., Jones M., Lye G., Moule S., Odell C. , Pearson D., Rajandream M.A., Rice P., Rowley N., Skelton J., Smith V., Walsh S.V., Whitehead S., Barrell B.G. Nature 387:84-87(1997) [PubMed: 9169870] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: ATCC 204511 / S288c / AB972.
[3]	Saccharomyces Genome Database Submitted (DEC-2009) to the EMBL/GenBank/DDBJ databases Cited for: GENOME REANNOTATION. Strain: ATCC 204508 / S288c.
[4]	"Studies on the microsomal electron-transport system of anaerobically grown yeast. IV. Purification and characterization of NADH-cytochrome b5 reductase." Kubota S., Yoshida Y., Kumaoka H. J. Biochem. 81:187-195(1977) [PubMed: 14930] [Abstract] Cited for: CHARACTERIZATION, BIOPHYSICOCHEMICAL PROPERTIES, ENZYME REGULATION, SUBUNIT.
[5]	"Influence of oxygen on the microsomal electron transport system in Saccharomyces cerevisiae." Bertrand J.-C., Mattei G., Parra C., Giordani R., Gilewicz M. Biochimie 66:583-588(1984) [PubMed: 6442167] [Abstract] Cited for: INDUCTION, ENZYME REGULATION.
[6]	"Biodiversity of the P450 catalytic cycle: yeast cytochrome b5/NADH cytochrome b5 reductase complex efficiently drives the entire sterol 14-demethylation (CYP51) reaction." Lamb D.C., Kelly D.E., Manning N.J., Kaderbhai M.A., Kelly S.L. FEBS Lett. 462:283-288(1999) [PubMed: 10622712] [Abstract] Cited for: FUNCTION.
[7]	"Sequencing and comparison of yeast species to identify genes and regulatory elements." Kellis M., Patterson N., Endrizzi M., Birren B.W., Lander E.S. Nature 423:241-254(2003) [PubMed: 12748633] [Abstract] Cited for: IDENTIFICATION OF PROBABLE INITIATION SITE.
[8]	"Global analysis of protein localization in budding yeast." Huh W.-K., Falvo J.V., Gerke L.C., Carroll A.S., Howson R.W., Weissman J.S., O'Shea E.K. Nature 425:686-691(2003) [PubMed: 14562095] [Abstract] Cited for: SUBCELLULAR LOCATION [LARGE SCALE ANALYSIS].
[9]	"Global analysis of protein expression in yeast." Ghaemmaghami S., Huh W.-K., Bower K., Howson R.W., Belle A., Dephoure N., O'Shea E.K., Weissman J.S. Nature 425:737-741(2003) [PubMed: 14562106] [Abstract] Cited for: LEVEL OF PROTEIN EXPRESSION [LARGE SCALE ANALYSIS].
[10]	"Mapping of transcription start sites in Saccharomyces cerevisiae using 5' SAGE." Zhang Z., Dietrich F.S. Nucleic Acids Res. 33:2838-2851(2005) [PubMed: 15905473] [Abstract] Cited for: IDENTIFICATION OF PROBABLE INITIATION SITE.
[11]	"Proteomic analysis of the yeast mitochondrial outer membrane reveals accumulation of a subclass of preproteins." Zahedi R.P., Sickmann A., Boehm A.M., Winkler C., Zufall N., Schoenfisch B., Guiard B., Pfanner N., Meisinger C. Mol. Biol. Cell 17:1436-1450(2006) [PubMed: 16407407] [Abstract] Cited for: SUBCELLULAR LOCATION, IDENTIFICATION BY MASS SPECTROMETRY.
[12]	"Proteins involved in sterol synthesis interact with Ste20 and regulate cell polarity." Tiedje C., Holland D.G., Just U., Hofken T. J. Cell Sci. 120:3613-3624(2007) [PubMed: 17895367] [Abstract] Cited for: INTERACTION WITH STE20.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	Z28365 Genomic DNA. Translation: CAA82214.1. Different initiation. Z46861 Genomic DNA. Translation: CAA86908.1. Different initiation. BK006942 Genomic DNA. Translation: DAA08505.1.
PIR	S49935.
RefSeq	NP_012221.2. NM_001179393.1.
3D structure databases
ProteinModelPortal	P38626.
SMR	P38626. Positions 29-284.
ModBase	Search...
Protein-protein interaction databases
IntAct	P38626. 21 interactions.
MINT	MINT-1324688.
STRING	P38626.
Proteomic databases
PeptideAtlas	P38626.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
EnsemblFungi	YIL043C; YIL043C; YIL043C.
GeneID	854768.
KEGG	sce:YIL043C.
NMPDR	fig|4932.3.peg.1754.
Organism-specific databases
SGD	S000001305. CBR1.
Phylogenomic databases
eggNOG	fuNOG05226.
GeneTree	EFGT00050000001026.
HOGENOM	HBG591994.
OMA	VRHFGMI.
OrthoDB	EOG4FFH9R.
Gene expression databases
ArrayExpress	P38626.
Genevestigator	P38626.
GermOnline	YIL043C. Saccharomyces cerevisiae.
Family and domain databases
InterPro	IPR017927. Fd_Rdtase_FAD-bd. IPR001709. Flavoprot_Pyr_Nucl_cyt_Rdtase. IPR001834. NADH-Cyt_B5_reductase. IPR008333. OxRdtase_FAD-bd_dom. IPR001433. OxRdtase_FAD/NAD-bd. IPR017938. Riboflavin_synthase-like_b-brl. [Graphical view]
KO	K00326.
Pfam	PF00970. FAD_binding_6. 1 hit. PF00175. NAD_binding_1. 1 hit. [Graphical view]
PRINTS	PR00406. CYTB5RDTASE. PR00371. FPNCR.
SUPFAM	SSF63380. Riboflavin_synthase_like_b-brl. 1 hit.
PROSITE	PS51384. FAD_FR. 1 hit. [Graphical view]
ProtoNet	Search...
Other
NextBio	977526.

Entry information

Entry name

NCB5R_YEAST

Accession

Primary (citable) accession number: P38626
Secondary accession number(s): D6VVN9

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 1, 1994
Last sequence update:	April 29, 2008
Last modified:	December 14, 2011
This is version 105 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Fungal Protein Annotation Program