17 β- hydroxysteroid dehydrogenase type 7

Hydroxysteroid 17 β -dehydrogenase type 7
Properties of human protein
Mass / length primary structure	341 amino acids
Isoforms	NP_057455
Identifier
Gene name	HSD17B7
External IDs	OMIM : 606756 ; UniProt : P56937 ;
Enzyme Classifications
EC, category	1.1.1.62 , oxidoreductase
Response type	Hydrogenation
Substrate	Estrone + NADPH / H +
Products	Estradiol + NADP +
EC, category	1.1.1.270 , oxidoreductase
Response type	Hydrogenation
Substrate	(Methyl) zymosterone
Products	(Methyl) zymosterol
Occurrence
Parent taxon	Mammals
	Orthologue

The 17 β -hydroxysteroid dehydrogenases type 7 (HSD17B7) are enzymes that convert estrone into estradiol and zymosterone into zymosterol ( enzyme activity 3 β- ketosteroid reductase ). The first reaction is a partial step in estrogen biosynthesis and the second a step in cholesterol biosynthesis . HSD17B7 is found in mammals and there are three isoforms in humans . HSD17B7 is known of eleven human hydroxysteroid 17 β -dehydrogenases .

The conversion of estrone to estradiol by HSD17B7 found in rodents and humans especially in the corpus luteum place where the other estradiol-17 β not -dehydrogenases (HSD17B1 and HSD16B12) expressed will. The ketosteroid reductase activity is indispensable for the formation of cholesterol , especially in the human placenta and in fetal development. Switching off HSD17B7 ( gene knockout ) achieved by genetic engineering leads to lethality in utero . The mouse fetuses die because they cannot produce cholesterol in the brain.

The HSD17B7 gene is located in humans on chromosome 10 gene locus p11.2. It spans about 22 kbases and contains 9 exons . HSD17B7 differs from other HSD17B enzymes through another loop that gives the molecule another name: prolactin receptor-associated protein.

Catalyzed reactions

+ NADPH / H ⁺ + NADP ⁺ ${\ displaystyle \ rightleftharpoons}$

Estrone is converted to estradiol.

+ NADPH / H ⁺ + NADP ⁺ ${\ displaystyle \ rightleftharpoons}$

Zymosterone is hydrogenated to zymosterol. In a further step in cholesterol biosynthesis, methylzymosterone is reduced to methylzymosterol.

Web links

Wikibooks: Biochemistry and Pathobiochemistry: Steroid Hormone Metabolism - Learning and Teaching Materials

D'Eustachio / reactome: Zymosterone (cholesta-8 (9), 24-dien-3-one) is reduced to zymosterol (cholesta-8 (9), 24-dien-3beta-ol)
D'Eustachio / reactome: 4-methylcholesta-8 (9), 24-dien-3-one is reduced to 4-methylcholesta-8 (9), 24-dien-3beta-ol

Individual evidence

↑ Marijanovic Z, Laubner D, Möller G et al : Closing the Gap: Identification of Human 3-Ketosteroid Reductase, the Last Unknown Enzyme of Mammalian Cholesterol Biosynthesis . In: Mol Endocrinol . 17, No. 9, August, pp. 1715-1725. doi : 10.1210 / me.2002-0436 .
↑ Ohnesorg T, Keller B, Hrabé de Angelis M et al : Transcriptional regulation of human and murine 17beta-hydroxysteroid dehydrogenase type-7 confers its participation in cholesterol biosynthesis . In: J Mol Endocrinol . 37, No. 1, August, pp. 185-197. PMID 16901934 . Retrieved April 29, 2010.
↑ ^a ^b Shehu A, Mao J, Gibori GB, et al : Prolactin receptor-associated protein / 17beta-hydroxysteroid dehydrogenase type 7 gene (Hsd17b7) plays a crucial role in embryonic development and fetal survival. . In: Mol Endocrinol . 22, No. 10, August, pp. 2268-2277. doi : 10.1210 / me.2008-0165 . PMID 1866942 .
↑ Liu H, Robert A, Luu-The V: Cloning and characterization of human form 2 type 7 17beta-hydroxysteroid dehydrogenase, a primarily 3beta-keto reductase and estrogen activating and androgen inactivating enzyme . In: J. Steroid Biochem. Mol. Biol . 94, No. 1-3, February 2005, pp. 173-9. doi : 10.1016 / j.jsbmb.2005.01.023 . PMID 15862963 .
↑ Törn S, Nokelainen P, Kurkela R, et al. : Production, purification, and functional analysis of recombinant human and mouse 17beta-hydroxysteroid dehydrogenase type 7 . In: Biochem. Biophys. Res. Commun. . 305, No. 1, May 2003, pp. 37-45. PMID 12732193 .

[marijanovic-1] Marijanovic Z, Laubner D, Möller G et al : Closing the Gap: Identification of Human 3-Ketosteroid Reductase, the Last Unknown Enzyme of Mammalian Cholesterol Biosynthesis . In: Mol Endocrinol . 17, No. 9, August, pp. 1715-1725. doi : 10.1210 / me.2002-0436 .

[ohn-2] Ohnesorg T, Keller B, Hrabé de Angelis M et al : Transcriptional regulation of human and murine 17beta-hydroxysteroid dehydrogenase type-7 confers its participation in cholesterol biosynthesis . In: J Mol Endocrinol . 37, No. 1, August, pp. 185-197. PMID 16901934 . Retrieved April 29, 2010.

[shehu-3] Shehu A, Mao J, Gibori GB, et al : Prolactin receptor-associated protein / 17beta-hydroxysteroid dehydrogenase type 7 gene (Hsd17b7) plays a crucial role in embryonic development and fetal survival. . In: Mol Endocrinol . 22, No. 10, August, pp. 2268-2277. doi : 10.1210 / me.2008-0165 . PMID 1866942 .

[liu-4] Liu H, Robert A, Luu-The V: Cloning and characterization of human form 2 type 7 17beta-hydroxysteroid dehydrogenase, a primarily 3beta-keto reductase and estrogen activating and androgen inactivating enzyme . In: J. Steroid Biochem. Mol. Biol . 94, No. 1-3, February 2005, pp. 173-9. doi : 10.1016 / j.jsbmb.2005.01.023 . PMID 15862963 .

[torn-5] Törn S, Nokelainen P, Kurkela R, et al. : Production, purification, and functional analysis of recombinant human and mouse 17beta-hydroxysteroid dehydrogenase type 7 . In: Biochem. Biophys. Res. Commun. . 305, No. 1, May 2003, pp. 37-45. PMID 12732193 .