Search by BoMiProt ID - Bomi35

Primary Information

BoMiProt ID Bomi35
Protein Name 3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase
Organism Bos taurus
Uniprot IDP14893
Milk FractionExosome
Ref Sequence ID NP_776768.1
Aminoacid Length 373
Molecular Weight 42220
FASTA Sequence Download
Gene Name HSD3B
Gene ID 281824
Protein Existence Status Reviewed: Experimental evidence at protein level

Secondary Information

Presence in other biological fluids/tissue/cells found in all steroidogenic tissues, including adrenal glands, testes, ovaries, and human placenta, brain, human epidermal keratinocytes, and in guinea pig kidneys; In humans, expression of the type I isoenzyme accounts for the 3 -HSD activity found in placenta and peripheral tissues, whereas the type II 3 -HSD isoenzyme is predominantly expressed in the adrenal gland, ovary, and testis
Protein Function catalyzes the conversion of the 3ß-hydroxy-∆5-steroids pregnenolone and dehydroepiandrosterope to the 3-keto-∆4-steroids progesterone and androstenedione, respectively; activity is essential for the production of all steroid hormones; responsible for the oxidation and isomerization of ∆5-3ß -hydroxysteroid precursors into ∆4- ketosteroids, thus catalyzing an essential step in the formation of all classes of active steroid hormones. Human placental 3β-hydroxysteroid dehydrogenase/steroid Δ5, 4-isomerase 1 (HSD3B1), a high-affinity type I enzyme, uses pregnenolone to make progesterone, which is critical for maintenance of pregnancy. 
Biochemical Properties it is possible that Ca2 could affect the mitochondrial to ER ratio of 3 -HSD; bovine zona glomerulosa cells showed that neither Ca2 nor Angiotensin-II had any effect on the subcellular distribution of 3 -HSD; two-step reaction of the 3 -HSD/isomerase involves the reduction of NAD to NADH by the rate-limiting 3 - HSD activity and the requirement of this NADH for the activation of the isomerase on the same enzyme
Significance in milk biosynthesis of active estrogens and androgens as found in normal human mammary epithelial cells
Site(s) of PTM(s)

N-glycosylation, O-glycosylation,
Predicted Disorder Regions 134-149,366-373
DisProt Annotation
TM Helix Prediction No TM helices
Additional Comments deficiency is responsible for a rare form of congenital adrenal hyperplasia
Bibliography 1. Thomas, J. L., Myers, R. P., & Strickler, R. C. (1989). Human placental 3 beta-hydroxy-5-ene-steroid dehydrogenase and steroid 5----4-ene-isomerase: purification from mitochondria and kinetic profiles, biophysical characterization of the purified mitochondrial and microsomal enzymes. Journal of Steroid Biochemistry, 33(2), 209–217.
2. Cherradi, N., Rossier, M. F., Vallotton, M. B., Timberg, R., Friedberg, I., Orly, J., … Capponi, A. M. (1997). Submitochondrial distribution of three key steroidogenic proteins (steroidogenic acute regulatory protein and cytochrome p450scc and 3beta-hydroxysteroid dehydrogenase isomerase enzymes) upon stimulation by intracellular calcium in adrenal glomerulosa cells. The Journal of Biological Chemistry, 272(12), 7899–7907.
3. Gingras, S., Moriggl, R., Groner, B., & Simard, J. (1999). Induction of 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase type 1 gene transcription in human breast cancer cell lines and in normal mammary epithelial cells by interleukin-4 and interleukin-13. Molecular Endocrinology (Baltimore, Md.), 13(1), 66–81.
4. Bain, P. A., Yoo, M., Clarke, T., Hammond, S. H., & Payne, A. H. (1991). Multiple forms of mouse 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase and differential expression in gonads, adrenal glands, liver, and kidneys of both sexes. Proceedings of the National Academy of Sciences of the United States of America, 88(20), 8870–8874.