Tags

Type your tag names separated by a space and hit enter

Exploring the active site of yeast xylose reductase by site-directed mutagenesis of sequence motifs characteristic of two dehydrogenase/reductase family types.
FEBS Lett. 2001 Jul 06; 500(3):149-52.FL

Abstract

Starting from a common tyrosine, yeast xylose reductases (XRs) contain two conserved sequence motifs corresponding to the catalytic signatures of single-domain reductases/epimerases/dehydrogenases (Tyr(n)-(X)3-Lys(n+4)) and aldo/keto reductases (AKRs) (Tyr(n)-(X)28-Lys(n+29)). Tyr(51), Lys(55) and Lys(80) of XR from Candida tenuis were replaced by site-directed mutagenesis. The purified Tyr(51)--> Phe and Lys(80)-->Ala mutants showed turnover numbers and catalytic efficiencies for NADH-dependent reduction of D-xylose between 2500- and 5000-fold below wild-type levels, suggesting a catalytic role of both residues. Replacing Lys(55) by Asn, a substitution found in other AKRs, did not detectably affect binding of coenzymes, and enzymatic catalysis to carbonyl/alcohol interconversion. The contribution of Tyr(51) to rate enhancement of aldehyde reduction conforms with expectations for the general acid catalyst of the enzymatic reaction.

Authors+Show Affiliations

Institute of Food Technology, University of Agricultural Sciences (BOKU), Muthgasse 18, A-1190, Vienna, Austria.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

11445075

Citation

Klimacek, M, et al. "Exploring the Active Site of Yeast Xylose Reductase By Site-directed Mutagenesis of Sequence Motifs Characteristic of Two Dehydrogenase/reductase Family Types." FEBS Letters, vol. 500, no. 3, 2001, pp. 149-52.
Klimacek M, Szekely M, Griessler R, et al. Exploring the active site of yeast xylose reductase by site-directed mutagenesis of sequence motifs characteristic of two dehydrogenase/reductase family types. FEBS Lett. 2001;500(3):149-52.
Klimacek, M., Szekely, M., Griessler, R., & Nidetzky, B. (2001). Exploring the active site of yeast xylose reductase by site-directed mutagenesis of sequence motifs characteristic of two dehydrogenase/reductase family types. FEBS Letters, 500(3), 149-52.
Klimacek M, et al. Exploring the Active Site of Yeast Xylose Reductase By Site-directed Mutagenesis of Sequence Motifs Characteristic of Two Dehydrogenase/reductase Family Types. FEBS Lett. 2001 Jul 6;500(3):149-52. PubMed PMID: 11445075.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Exploring the active site of yeast xylose reductase by site-directed mutagenesis of sequence motifs characteristic of two dehydrogenase/reductase family types. AU - Klimacek,M, AU - Szekely,M, AU - Griessler,R, AU - Nidetzky,B, PY - 2001/7/11/pubmed PY - 2001/8/10/medline PY - 2001/7/11/entrez SP - 149 EP - 52 JF - FEBS letters JO - FEBS Lett VL - 500 IS - 3 N2 - Starting from a common tyrosine, yeast xylose reductases (XRs) contain two conserved sequence motifs corresponding to the catalytic signatures of single-domain reductases/epimerases/dehydrogenases (Tyr(n)-(X)3-Lys(n+4)) and aldo/keto reductases (AKRs) (Tyr(n)-(X)28-Lys(n+29)). Tyr(51), Lys(55) and Lys(80) of XR from Candida tenuis were replaced by site-directed mutagenesis. The purified Tyr(51)--> Phe and Lys(80)-->Ala mutants showed turnover numbers and catalytic efficiencies for NADH-dependent reduction of D-xylose between 2500- and 5000-fold below wild-type levels, suggesting a catalytic role of both residues. Replacing Lys(55) by Asn, a substitution found in other AKRs, did not detectably affect binding of coenzymes, and enzymatic catalysis to carbonyl/alcohol interconversion. The contribution of Tyr(51) to rate enhancement of aldehyde reduction conforms with expectations for the general acid catalyst of the enzymatic reaction. SN - 0014-5793 UR - https://www.unboundmedicine.com/medline/citation/11445075/Exploring_the_active_site_of_yeast_xylose_reductase_by_site_directed_mutagenesis_of_sequence_motifs_characteristic_of_two_dehydrogenase/reductase_family_types_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0014-5793(01)02609-6 DB - PRIME DP - Unbound Medicine ER -