Reviewed, UniProtKB/Swiss-Prot O46516 (3BHS_HORSE)

Names and origin

Protein names

Recommended name:
    3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase
      Short name=3-beta-HSD
Including the following 2 domains:
    1- Recommended name:
            3-beta-hydroxy-Delta(5)-steroid dehydrogenase
              EC=1.1.1.145
        Alternative name(s):
            3-beta-hydroxy-5-ene steroid dehydrogenase
            Progesterone reductase
    2- Recommended name:
            Steroid Delta-isomerase
              EC=5.3.3.1
        Alternative name(s):
            Delta-5-3-ketosteroid isomerase

Gene names

Name:

HSD3B

Organism

Equus caballus (Horse)

Taxonomic identifier

9796 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Laurasiatheria › Perissodactyla › Equidae › Equus

Protein attributes

Sequence length	373 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at transcript level.

General annotation (Comments)

Function	3-beta-HSD is a bifunctional enzyme, that catalyzes the oxidative conversion of Delta(5)-ene-3-beta-hydroxy steroid, and the oxidative conversion of ketosteroids. The 3-beta-HSD enzymatic system plays a crucial role in the biosynthesis of all classes of hormonal steroids.
Catalytic activity	A 3-beta-hydroxy-Delta(5)-steroid + NAD+ = a 3-oxo-Delta(5)-steroid + NADH. A 3-oxo-Delta(5)-steroid = a 3-oxo-Delta(4)-steroid.
Pathway	Lipid metabolism; steroid biosynthesis.
Subcellular location	Endoplasmic reticulum membrane; Single-pass membrane protein. Mitochondrion membrane; Single-pass membrane protein.
Sequence similarities	Belongs to the 3-beta-HSD family.

Ontologies

Keywords
Biological process	Steroidogenesis
Cellular component	Endoplasmic reticulum Membrane Mitochondrion
Domain	Transmembrane
Ligand	NAD
Molecular function	Isomerase Oxidoreductase
Technical term	Multifunctional enzyme
Gene Ontology (GO)
Biological process	oxidation reduction Inferred from electronic annotation. Source: UniProtKB-KW steroid biosynthetic process Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	endoplasmic reticulum Inferred from electronic annotation. Source: UniProtKB-KW integral to membrane Inferred from electronic annotation. Source: UniProtKB-SubCell mitochondrion Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	3-beta-hydroxy-delta5-steroid dehydrogenase activity Inferred from electronic annotation. Source: EC binding Inferred from electronic annotation. Source: InterPro steroid delta-isomerase activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Initiator methionine	1	1	Removed By similarity
	Chain	2 – 373	372	3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase		PRO_0000087773
Regions
	Transmembrane	288 – 308	21	Potential
Sites
	Active site	155	1	Proton acceptor By similarity
	Binding site	159	1	NAD By similarity

Sequences

	Sequence		Length	Mass (Da)
	O46516-1 [UniParc]. Last modified January 23, 2007. Version 3. Checksum: 837A04E3C681417C	FASTA	373	42,411
	10 20 30 40 50 60 MAGWSCLVTG AGGFLGQRIV RLLVEEKEVQ EIRALDKVFR PELREEFSKL QSKVKLTVLE 70 80 90 100 110 120 GDILDEQFLK RACQGASAVI HTASIIDVTN LFNPQVTMNV NVEGTQLLLE ACSQASVPIF 130 140 150 160 170 180 IYTSSVAVAG PNSYREIIQN GHEEAHLETK WSSPYPYSKK LAEKAVLAAN GLPLKNGGTL 190 200 210 220 230 240 YTCALRPMFI YGEGSPTLYY LMHEGLNNNG ILTHNCKFSR ANPVYVGNIA WAHIMALRAL 250 260 270 280 290 300 RDPKKAPSIQ GQFYYISDDT PPQSYDDLTY TLSKKWGFCL DSRMRLPIFL KYWLAFLLEI 310 320 330 340 350 360 VSFLLSPIYK YRPPFDRHLV TWQNSVFTFS YKKAQRDMGY EPLFSWEEAK KRTTEWIDAL 370 VEPHQEALKT KTL

References

[1]	"Equine P450 cholesterol side-chain cleavage and 3 beta-hydroxysteroid dehydrogenase/delta(5)-delta(4) isomerase: molecular cloning and regulation of their messenger ribonucleic acids in equine follicles during the ovulatory process." Boerboom D., Sirois J. Biol. Reprod. 64:206-215(2001) [PubMed: 11133676] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Ovarian follicle membrane.
[2]	"Molecular cloning, nucleotide sequence and tissue distribution of equine testicular 3 beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase messenger ribonucleic acid." Hasegawa T., Ishida M., Harigaya T., Ishida N., Mukoyama H. J. Equine Sci. 9:45-52(1998) Cited for: NUCLEOTIDE SEQUENCE [MRNA].

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF031665 mRNA. Translation: AAC04701.1. D89666 mRNA. Translation: BAA32698.1.
RefSeq	NP_001075380.1.
UniGene	Eca.12081
3D structure databases
SMR	O46516. Positions 5-358.
ModBase	Search...
Genome annotation databases
Ensembl	ENSECAT00000015327; ENSECAP00000012310; ENSECAG00000014483; Equus caballus. [Genome view]
GeneID	100034078.
KEGG	ecb:100034078.
Organism-specific databases
CTD	100034078.
Phylogenomic databases
HOVERGEN	O46516.
InParanoid	O46516.
Enzyme and pathway databases
BRENDA	1.1.1.145. 1464. 5.3.3.1. 1464.
Family and domain databases
InterPro	IPR016040. NAD(P)-bd_dom. [Graphical view]
Gene3D	G3DSA:3.40.50.720. NAD(P)-bd. 1 hit.
ProtoNet	Search...

Entry information

Entry name

3BHS_HORSE

Accession

Primary (citable) accession number: O46516
Secondary accession number(s): P79437

Entry history

Integrated into UniProtKB/Swiss-Prot:	December 1, 2000
Last sequence update:	January 23, 2007
Last modified:	February 9, 2010
This is version 73 of the entry and version 3 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HPI (Human Proteome Initiative)