OXP1/YKL215c encodes an ATP-dependent 5-oxoprolinase in Saccharomyces cerevisiae: functional characterization, domain structure and identification of actin-like ATP-binding motifs in eukaryotic 5-oxoprolinases.

Kumar, Akhilesh and Bachhawat, Anand K (2010) OXP1/YKL215c encodes an ATP-dependent 5-oxoprolinase in Saccharomyces cerevisiae: functional characterization, domain structure and identification of actin-like ATP-binding motifs in eukaryotic 5-oxoprolinases. FEMS yeast research, 10 (4). pp. 394-401. ISSN 1567-1364

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Abstract

OXP1/YKL215c, an uncharacterized ORF of Saccharomyces cerevisiae, encodes a functional ATP-dependent 5-oxoprolinase of 1286 amino acids. The yeast 5-oxoprolinase activity was demonstrated in vivo by utilization of 5-oxoproline as a source of glutamate and OTC, a 5-oxoproline sulfur analogue, as a source of sulfur in cells overexpressing OXP1. In vitro characterization by expression and purification of the recombinant protein in S. cerevisiae revealed that the enzyme exists and functions as a dimer, and has a K(m) of 159 microM and a V(max) of 3.5 nmol h(-1) microg(-1) protein. The enzyme was found to be functionally separable in two distinct domains. An 'actin-like ATPase motif' could be identified in 5-oxprolinases, and mutation of key residues within this motif led to complete loss in ATPase and 5-oxoprolinase activity of the enzyme. The results are discussed in the light of the previously postulated truncated gamma-glutamyl cycle of yeasts.

Item Type:	Article
Additional Information:	Copyright of this article belongs to Wiley
Uncontrolled Keywords:	glutathione; 5-oxoprolinase; 5-oxoproline; g-glutamyl cycle; actin-like ATPase domain; OXP1.
Subjects:	Q Science > QR Microbiology
Depositing User:	Dr. K.P.S.Sengar
Date Deposited:	08 Dec 2011 19:22
Last Modified:	28 Mar 2012 09:30
URI:	http://crdd.osdd.net/open/id/eprint/520

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