Fine 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 ⁺

Journal Article · Tue Jan 11 04:00:00 EST 2005 · FEBS Letters

DOI:https://doi.org/10.1016/j.febslet.2004.12.063· OSTI ID:890432

Leitgeb, Stefan; Petschacher, Barbara; Wilson, David K.; Nidetzky, Bernd

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 2.3 Å, 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.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 890432
• Report Number(s): SLAC-REPRINT-2005-075
• Journal Information: FEBS Letters, Journal Name: FEBS Letters Journal Issue: 3 Vol. 579; ISSN 0014-5793
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CANDIDA
COENZYMES
CRYSTAL STRUCTURE
MUTANTS
OXIDOREDUCTASES
SPECIFICITY
TUNING
XYLOSE