Role of invariant water molecules and water-mediated ionic interactions in D-xylose isomerase from Streptomyces rubiginosus.

V Dhanasekaran, D Velmurugan, Shankar Prasad Kanaujia, K Sekar

Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, India.

Journal of biomolecular structure & dynamics 2013 Apr

filter terms:

The enzyme, D-xylose isomerase (D-xylose keto-isomerase; EC 5.3.1.5) is a soluble enzyme that catalyzes the conversion of the aldo-sugar D-xylose to the keto-sugar D-xylulose. A total of 27 subunits of D-xylose isomerase from Streptomyces rubiginosus were analyzed in order to identify the invariant water molecules and their water-mediated ionic interactions. A total of 70 water molecules were found to be invariant. The structural and/or functional roles of these water molecules have been discussed. These invariant water molecules and their ionic interactions may be involved in maintaining the structural stability of the enzyme D-xylose isomerase. Fifty-eight of the 70 invariant water molecules (83%) have at least one interaction with the main chain polar atom.

Citation

V Dhanasekaran, D Velmurugan, Shankar Prasad Kanaujia, K Sekar. Role of invariant water molecules and water-mediated ionic interactions in D-xylose isomerase from Streptomyces rubiginosus. Journal of biomolecular structure & dynamics. 2013 Apr;31(4):376-84