Reviewed, UniProtKB/Swiss-Prot Q28CZ9 (NB5R4_XENTR)

Names and origin

Protein names

Recommended name:
    Cytochrome b5 reductase 4
    EC=1.6.2.2
Alternative name(s):
    Flavohemoprotein b5/b5R
      Short name=b5+b5R
    cb5/cb5R

Gene names

Name:	cyb5r4
ORF Names:	TGas070l21.1

Organism

Xenopus tropicalis (Western clawed frog) (Silurana tropicalis)

Taxonomic identifier

8364 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Amphibia › Batrachia › Anura › Mesobatrachia › Pipoidea › Pipidae › Xenopodinae › Xenopus › Silurana

Protein attributes

Sequence length	523 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at transcript level.

General annotation (Comments)

Function	NADH-cytochrome b5 reductase involved in endolasmic reticulum stress response pathway By similarity.
Catalytic activity	NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5.
Cofactor	FAD By similarity.
Subcellular location	Endoplasmic reticulum. Note: Soluble protein By similarity.
Sequence similarities	Belongs to the flavoprotein pyridine nucleotide cytochrome reductase family. Contains 1 CS domain. Contains 1 cytochrome b5 heme-binding domain. Contains 1 FAD-binding FR-type domain.

Ontologies

Keywords
Cellular component	Endoplasmic reticulum
Ligand	FAD Flavoprotein Heme Iron Metal-binding NAD
Molecular function	Oxidoreductase
Gene Ontology (GO)
Biological process	oxidation reduction Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	endoplasmic reticulum Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	cytochrome-b5 reductase activity Inferred from electronic annotation. Source: EC electron carrier activity Inferred from electronic annotation. Source: InterPro 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
	Chain	1 – 523	523	Cytochrome b5 reductase 4		PRO_0000287560
Regions
	Domain	54 – 130	77	Cytochrome b5 heme-binding
	Domain	167 – 258	92	CS
	Domain	275 – 387	113	FAD-binding FR-type
	Nucleotide binding	367 – 382	16	FAD By similarity
	Nucleotide binding	394 – 426	33	FAD By similarity
Sites
	Metal binding	89	1	Iron (heme axial ligand) By similarity
	Metal binding	112	1	Iron (heme axial ligand) By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q28CZ9-1 [UniParc]. Last modified April 4, 2006. Version 1. Checksum: BF4CEECC9085903C	FASTA	523	59,216
	10 20 30 40 50 60 MLNVPSQSFP APSSQQRVAA IGRSKVPLKP GRSLMDWIRL TKSGKDLTGL KGRLIDVTEE 70 80 90 100 110 120 ELAQHNKKED CWICIRGMVY NITPYMEYHP GGEEELMKAA GRDGTDLFDQ VHRWVNYESM 130 140 150 160 170 180 LKECLIGRMA IKHVSISKEV TSVENKMNKH LNGSVASSKM SRTSSKESHP WYDWFQTESL 190 200 210 220 230 240 VTVAVYTKMK NVCSELVIVD HLENVLRGEI IIGDYSYLLH SELSHPVQKD IEVKVSATAG 250 260 270 280 290 300 KIEIKMKKKE PVSWKSLGQP MDGHNSFLKH SQRGLYYRKC RLASKTDINY NTKLFCVQLP 310 320 330 340 350 360 QGCHLQVPVG HHIYLKMNIS GVDIVKPYTP VASCLLPDAQ YSTFCNKQCL YLMIKIYPNG 370 380 390 400 410 420 SITPHLENLT VGDYISISNP QGTFSSFQIE NVMDVFLVAA GTGITPMIRL LQHVLTCVSS 430 440 450 460 470 480 LRKAKLIFFN KKEEDILWKE QVEELSLADK RFEAQLILSE PSVKWTGYRG QISYSLLNES 490 500 510 520 ILRTEEGSKI LICICGPNAF VDQGISFLQD LGFSKEEVFA FRE

References

[1]	Sanger Xenopus tropicalis EST/cDNA project Submitted (OCT-2006) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Tissue: Gastrula.

Cross-references

Sequence databases
EMBLGenBankDDBJ	CR855785 mRNA. Translation: CAJ83762.1.
RefSeq	NP_001016756.1.
UniGene	Str.27458
3D structure databases
ModBase	Search...
Genome annotation databases
GeneID	549510.
KEGG	xtr:549510.
Organism-specific databases
Xenbase	XB-FEAT-984178. cyb5r4.
Phylogenomic databases
HOVERGEN	Q28CZ9.
OMA	Q28CZ9. LIKIYPA.
Enzyme and pathway databases
BRENDA	1.6.2.2. 279072.
Family and domain databases
InterPro	IPR017447. CS. IPR007052. CS_domain. IPR001199. Cyt_B5. IPR018506. Cyt_B5_heme-BS. IPR017927. Fd_Rdtase_FAD-bd. IPR001834. NADH-Cyt_B5_reductase. IPR008333. OxRdtase_FAD-bd. IPR001433. OxRdtase_FAD/NAD_bd. [Graphical view]
Gene3D	G3DSA:3.10.120.10. Cyt_B5. 1 hit.
Pfam	PF04969. CS. 1 hit. PF00173. Cyt-b5. 1 hit. PF00970. FAD_binding_6. 1 hit. PF00175. NAD_binding_1. 1 hit. [Graphical view]
PRINTS	PR00406. CYTB5RDTASE. PR00363. CYTOCHROMEB5.
ProDom	PD000612. Cyt_B5. 1 hit. [Graphical view] [Entries sharing at least one domain]
PROSITE	PS51203. CS. 1 hit. PS00191. CYTOCHROME_B5_1. 1 hit. PS50255. CYTOCHROME_B5_2. 1 hit. PS51384. FAD_FR. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

NB5R4_XENTR

Accession

Primary (citable) accession number: Q28CZ9

Entry history

Integrated into UniProtKB/Swiss-Prot:	May 15, 2007
Last sequence update:	April 4, 2006
Last modified:	June 16, 2009
This is version 31 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Xenopus annotation project