کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2030414 1071101 2006 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structure-Guided Engineering of Xylitol Dehydrogenase Cosubstrate Specificity
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Structure-Guided Engineering of Xylitol Dehydrogenase Cosubstrate Specificity
چکیده انگلیسی

SummaryXylitol dehydrogenase (XDH) is one of several enzymes responsible for assimilating xylose into eukaryotic metabolism and is useful for fermentation of xylose contained in agricultural byproducts to produce ethanol. For efficient xylose utilization at high flux rates, cosubstrates should be recycled between the NAD+-specific XDH and the NADPH-preferring xylose reductase, another enzyme in the pathway. To understand and alter the cosubstrate specificity of XDH, we determined the crystal structure of the Gluconobacter oxydans holoenzyme to 1.9 Å resolution. The structure reveals that NAD+ specificity is largely conferred by Asp38, which interacts with the hydroxyls of the adenosine ribose. Met39 stacked under the purine ring and was also located near the 2′ hydroxyl. Based on the location of these residues and on sequence alignments with related enzymes of various cosubstrate specificities, we constructed a double mutant (D38S/M39R) that was able to exclusively use NADP+, with no loss of activity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 14, Issue 3, March 2006, Pages 567–575
نویسندگان
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