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Crystal structure of cis‐biphenyl‐2,3‐dihydrodiol‐2,3‐dehydrogenase from a PCB degrader at 2.0 Å resolution
Author(s) -
Hülsmeyer Martin,
Hecht HansJürgen,
Niefind Karsten,
Schomburg Dietmar,
Hofer Bernd,
Timmis Kenneth N.,
Eltis Lindsay D.
Publication year - 1998
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.5560070603
Subject(s) - cofactor , biphenyl , nad+ kinase , dehydrogenase , chemistry , oxidoreductase , stereochemistry , moiety , alcohol dehydrogenase , enzyme , substrate (aquarium) , catalytic triad , nicotinamide , polychlorinated biphenyl , active site , biochemistry , biology , organic chemistry , ecology
cis ‐Biphenyl‐2,3‐dihydrodiol‐2,3‐dehydrogenase (BphB) is involved in the aerobic biodegradation of polychlorinated biphenyls (PCBs). The crystal structure of the NAD + ‐enzyme complex was determined by molecular replacement and refined to an R‐value of 17.9% at 2.0 Å. As a member of the short‐chain alcohol dehydrogenase/reductase (SDR) family, the overall protein fold and positioning of the catalytic triad in BphB are very similar to those observed in other SDR enzymes, although small differences occur in the cofactor binding site. Modeling studies indicate that the substrate is bound in a deep hydrophobic cleft close to the nicotinamide moiety of the NAD + cofactor. These studies further suggest that Asn143 is a key determinant of substrate specificity. A two‐step reaction mechanism is proposed for cis ‐dihydrodiol dehydrogenases.