1n5d
CRYSTAL STRUCTURE OF PORCINE TESTICULAR CARBONYL REDUCTASE/ 20BETA-HYDROXYSTEROID DEHYDROGENASE
OverviewOverview
Porcine testicular carbonyl reductase (PTCR) belongs to the short chain dehydrogenases/reductases (SDR) superfamily and catalyzes the NADPH-dependent reduction of ketones on steroids and prostaglandins. The enzyme shares nearly 85% sequence identity with the NADPH-dependent human 15-hydroxyprostaglandin dehydrogenase/carbonyl reductase. The tertiary structure of the enzyme at 2.3 A reveals a fold characteristic of the SDR superfamily that uses a Tyr-Lys-Ser triad as catalytic residues, but exhibits neither the functional homotetramer nor the homodimer that distinguish all SDRs. It is the first known monomeric structure in the SDR superfamily. In PTCR, which is also active as a monomer, a 41-residue insertion immediately before the catalytic Tyr describes an all-helix subdomain that packs against interfacial helices, eliminating the four-helix bundle interface conserved in the superfamily. An additional anti-parallel strand in the PTCR structure also blocks the other strand-mediated interface. These novel structural features provide the basis for the scaffolding of one catalytic site within a single molecule of the enzyme.
About this StructureAbout this Structure
1N5D is a Single protein structure of sequence from Sus scrofa. This structure supersedes the now removed PDB entry 1hu4. Full crystallographic information is available from OCA.
ReferenceReference
Porcine carbonyl reductase. structural basis for a functional monomer in short chain dehydrogenases/reductases., Ghosh D, Sawicki M, Pletnev V, Erman M, Ohno S, Nakajin S, Duax WL, J Biol Chem. 2001 May 25;276(21):18457-63. Epub 2001 Mar 8. PMID:11279087 Page seeded by OCA on Sat May 3 02:06:53 2008