Structural role of conserved Asn179 in the short-chain dehydrogenase/reductase scaffold
2001 (English)In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 289, no 3, 712-717 p.Article in journal (Refereed) Published
Short-chain dehydrogenases/reductases (SDR) constitute a large family of enzymes found in all forms of life. Despite a low level of sequence identity, the three-dimensional structures determined display a nearly superimposable alpha/beta folding pattern. We identified a conserved asparagine residue located within strand betaF and analyzed its role in the short-chain dehydrogenase/reductase architecture. Mutagenetic replacement of Asn179 by Ala in bacterial 3 beta /17 beta -hydroxysteroid dehydrogenase yields a folded, but enzymatically inactive enzyme, which is significantly more resistant to denaturation by guanidinium hydrochloride. Crystallographic analysis of the wild-type enzyme at 1.2-Angstrom resolution reveals a hydrogen bonding network, including a buried and well-ordered water molecule connecting strands betaE to betaF, a common feature found in 16 of 21 known three-dimensional structures of the family. Based on these results, we hypothesize that in mammalian 11 beta -hydroxysteroid dehydrogenase the essential Asn-linked glycosylation site, which corresponds to the conserved segment, displays similar structural features and has a central role to maintain the SDR scaffold.
Place, publisher, year, edition, pages
2001. Vol. 289, no 3, 712-717 p.
Biochemistry and Molecular Biology Biophysics
IdentifiersURN: urn:nbn:se:sh:diva-15836DOI: 10.1006/bbrc.2001.6032ISI: 000172751600012PubMedID: 11726206ScopusID: 2-s2.0-0035824597OAI: oai:DiVA.org:sh-15836DiVA: diva2:509042