Back to Search
Start Over
Three-dimensional structure of holo 3 alpha,20 beta-hydroxysteroid dehydrogenase: a member of a short-chain dehydrogenase family
- Source :
- Proceedings of the National Academy of Sciences. 88:10064-10068
- Publication Year :
- 1991
- Publisher :
- Proceedings of the National Academy of Sciences, 1991.
-
Abstract
- The x-ray structure of a short-chain dehydrogenase, the bacterial holo 3 alpha,20 beta-hydroxysteroid dehydrogenase (EC 1.1.1.53), is described at 2.6 A resolution. This enzyme is active as a tetramer and crystallizes with four identical subunits in the asymmetric unit. It has the alpha/beta fold characteristic of the dinucleotide binding region. The fold of the rest of the subunit, the quaternary structure, and the nature of the cofactor-enzyme interactions are, however, significantly different from those observed in the long-chain dehydrogenases. The architecture of the postulated active site is consistent with the observed stereospecificity of the enzyme and the fact that the tetramer is the active form. There is only one cofactor and one substrate-binding site per subunit; the specificity for both 3 alpha- and 20 beta-ends of the steroid results from the binding of the steroid in two orientations near the same cofactor at the same catalytic site.
- Subjects :
- Macromolecular Substances
Protein Conformation
Stereochemistry
Protein subunit
Cortisone Reductase
Molecular Sequence Data
Molecular Conformation
Dehydrogenase
Cofactor
Substrate Specificity
Protein structure
X-Ray Diffraction
Tetramer
Sequence Homology, Nucleic Acid
Computer Graphics
Amino Acid Sequence
Short-chain dehydrogenase
Multidisciplinary
Bacteria
biology
Chemistry
Active site
Biochemistry
biology.protein
Protein quaternary structure
Oxidoreductases
Research Article
Subjects
Details
- ISSN :
- 10916490 and 00278424
- Volume :
- 88
- Database :
- OpenAIRE
- Journal :
- Proceedings of the National Academy of Sciences
- Accession number :
- edsair.doi.dedup.....c54dca89bcbc3ff63760bbdb8c38d385