1ZEM

Crystal Structure of NAD+-Bound Xylitol Dehydrogenase

Summary for 1ZEM

• Entry DOI: 10.2210/pdb1zem/pdb
• Descriptor: xylitol dehydrogenase, NICOTINAMIDE-ADENINE-DINUCLEOTIDE, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: rossmann fold, dinucleotide-binding domain, oxidoreductase
• Biological source: Gluconobacter oxydans
• Total number of polymer chains: 8
• Total formula weight: 228274.91

Authors

Ehrensberger, A.H.,Elling, R.A.,Wilson, D.K. (deposition date: 2005-04-19, release date: 2006-03-28, Last modification date: 2023-08-23)

Primary citation

Ehrensberger, A.H.,Elling, R.A.,Wilson, D.K.
Structure-guided engineering of xylitol dehydrogenase cosubstrate specificity.
Structure, 14:567-575, 2006

PubMed Abstract: Xylitol 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 angstroms 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.

PubMed: 16531240
DOI: 10.1016/j.str.2005.11.016

Experimental method

X-RAY DIFFRACTION (1.9 Å)