Structure of bacterial 3 beta/17 beta-hydroxysteroid dehydrogenase at 1.2 angstrom resolution: A model for multiple steroid recognition
2002 (English)In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 41, no 50, 14659-14668 p.Article in journal (Refereed) Published
The enzyme 3beta/17beta-hydroxysteroid dehydrogenase (3beta/17beta-HSD) is a steroid-inducible component of the Gram-negative bacterium Conramonas testosteroni. It catalyzes the reversible reduction/ dehydrogenation of the oxo/beta-hydroxy groups at positions 3 and 17 of steroid compounds, including hormones and isobile acids. Crystallographic analysis at 1.2 Angstrom resolution reveals the enzyme to have nearly identical subunits that form a tetramer with 222 symmetry. This is one of the largest oligomeric structures refined at this resolution. The subunit consists of a monomer with a single-domain structure built around a seven-stranded beta-sheet flanked by six alpha-helices. The active site contains a Ser-Tyr-Lys triad, typical for short-chain dehydrogenases/reductases (SDR). Despite their highly diverse substrate specificities, SDR members show a close to identical folding pattern architectures and a common catalytic mechanism. In contrast to other SDR apostructures determined, the substrate binding loop is well-defined. Analysis of structure-activity relationships of catalytic cleft residues, docking analysis of substrates and inhibitors, and accessible surface analysis explains how 3beta/17beta-HSD accommodates steroid substrates of different conformations.
Place, publisher, year, edition, pages
2002. Vol. 41, no 50, 14659-14668 p.
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:sh:diva-15720DOI: 10.1021/bi0203684ISI: 000179817200005PubMedID: 12475215ScopusID: 2-s2.0-0037126640OAI: oai:DiVA.org:sh-15720DiVA: diva2:508297