Linked Life Data

12604235

Source:http://linkedlifedata.com/resource/pubmed/id/12604235

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2003-2-26
pubmed:abstractText
17beta-Hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17beta-HSDcl) is a NADPH dependent member of the short-chain dehydrogenase reductase (SDR) superfamily. Recently, we prepared a homology-built structural model of 17beta-HSDcl using the known three-dimensional structure of homologous 1,3,8-trihydroxynaphthalene reductase from the fungus Magnaporthe grisea. This model structure directed our studies of structure-function relationship of the fungal 17beta-HSD, as one of the model enzymes of the SDR superfamily. In this work, we investigated the significance of individual amino acid residues for coenzyme and substrate specificity. We performed site directed mutagenesis of R28, a basic residue conserved in most NADPH dependent SDR structures; T200, found only in Streptomyces hydrogenans 3alpha,20beta-HSD and Drosophila alcohol dehydrogenases; and H230, a residue corresponding to the substrate specificity important H221 in human 17beta-HSD type 1. All recombinant proteins were expressed in Escherichia coli and purified to homogeneity. Kinetic evaluation of individual mutations was performed by analysis of progress curves of interconversions between 4-estrene-3,17-dione and 4-estrene-17beta-ol-3-one, in the presence of NADPH and NADP(+); according to the Theorell-Chance reaction mechanism. The results demonstrate the role of the selected amino acid residues; R28 seems to interact with the NADPH 2'-phosphate group; T200 may be involved in binding and dissociation of NADPH/NADP(+); while H230 and the neighboring A231 appears not to be responsible for substrate specificity of 17beta-HSDcl.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0009-2797
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
143-144
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
493-501
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Significance of individual amino acid residues for coenzyme and substrate specificity of 17beta-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus.
pubmed:affiliation
Medical Faculty, Institute of Biochemistry, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't