Download MendeleyFine tuning of coenzyme specificity in family 2 aldo-keto reductases revealed by crystal structures of the Lys-274-->Arg mutant of Candida tenuis xylose reductase (AKR2B5) bound to NAD(+) and NADP(+).
Leitgeb, S., Petschacher, B., Wilson, D.K., Nidetzky, B.(2005) FEBS Lett 579: 763-767
- PubMed: 15670843
- DOI: https://doi.org/10.1016/j.febslet.2004.12.063
- Primary Citation of Related Structures:
1YE4, 1YE6 - PubMed Abstract:
Aldo-keto reductases of family 2 employ single site replacement Lys-->Arg to switch their cosubstrate preference from NADPH to NADH. X-ray crystal structures of Lys-274-->Arg mutant of Candida tenuis xylose reductase (AKR2B5) bound to NAD+ and NADP+ were determined at a resolution of 2.4 and 2.3A, respectively. Due to steric conflicts in the NADP+-bound form, the arginine side chain must rotate away from the position of the original lysine side chain, thereby disrupting a network of direct and water-mediated interactions between Glu-227, Lys-274 and the cofactor 2'-phosphate and 3'-hydroxy groups. Because anchoring contacts of its Glu-227 are lost, the coenzyme-enfolding loop that becomes ordered upon binding of NAD(P)+ in the wild-type remains partly disordered in the NADP+-bound mutant. The results delineate a catalytic reaction profile for the mutant in comparison to wild-type.
Organizational Affiliation:
Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/I, A-8010 Graz, Austria.
