Author/Editor     Lanišnik-Rižner, T; Stojan, J; Adamski, J
Title     17beta-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus: structural and functional aspects
Type     članek
Source     Chem Biol Interact
Vol. and No.     Letnik 130-2, št. 1-3
Publication year     2001
Volume     str. 793-803
ISSN     0009-2797
Language     eng
Abstract     17beta-Hydroxysteroid dehydrogenase (17beta-HSD) activity has been described in all filamentous fungi tested, but until now only one 17beta-HSD from Cochliobolus lunatus (17beta-HSDcl) was sequenced. We examined the evolutionary relationship among 17beta-HSDcl, fungal reductases, versicolorin reductase (Ver1), trihydroxynaphthalene reductase (THNR), and other homologous proteins. In the phylogenetic tree 17beta-HSDcl formed a separate branch with Ver1, while THNRs reside in another branch, indicating that 17beta-HSDcl could have similar function as Ver1. The structural relationship was investigated by comparing a model structure of 17beta-HSDcl to several known crystal structures of the short chain dehydrogenase/reductase (SDR) family. A similarity was observed to structures of bacterial 7alpha-HSD and plant tropinone reductase (TR). Additionally, substrate specificity revealed that among the substrates tested the 17beta-HSDcl preferentially catalyzed reductions of steroid substrates with a 3-keto group, Delta(4) or 5alpha, such as: 4-estrene-3,17-dione and 5alpha-androstane-3,17-dione.
Descriptors     17-HYDROXYSTEROID DEHYDROGENASES
ASCOMYCETES
MODELS, MOLECULAR
PHYLOGENY
PROTEIN CONFORMATION
SUBSTRATE SPECIFICITY