Molecular cloning and biochemical characterization of a 3'(2'),5'-bisphosphate nucleotidase from Debaryomyces hansenii.

Aggarwal, Monika and Bansal, P K and Mondal, Alok K (2005) Molecular cloning and biochemical characterization of a 3'(2'),5'-bisphosphate nucleotidase from Debaryomyces hansenii. Yeast (Chichester, England), 22 (6). pp. 457-70. ISSN 0749-503X

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Abstract

The enzyme 3'(2'),5'-bisphosphate nucleotidase catalyses a reaction that converts 3'-phosphoadenosine-5'-phosphate (PAP) to adenosine-5'-phosphate (AMP) and inorganic phosphate (Pi). The enzyme from Saccharomyces cerevisiae is highly sensitive to sodium and lithium and is thus considered to be the in vivo target of salt toxicity in yeast. In S. cerevisiae, the HAL2 gene encodes this enzyme. We have cloned a homologous gene, DHAL2, from the halotolerant yeast Debaryomyces hansenii. DNA sequencing of this clone revealed a 1260 bp open reading frame (ORF) that putatively encoded a protein of 420 amino acid residues. S. cerevisiae transformed with DHAL2 gene displayed higher halotolerance. Biochemical studies showed that recombinant Dhal2p could efficiently utilize PAP (K(m)17 microM) and PAPS (K(m)48 microM) as substrate. Moreover, we present evidence that, in comparison to other homologues from yeast, Dhal2p displays significantly higher resistance towards lithium and sodium ions.

Item Type:	Article
Additional Information:	Copyright of this article belongs to Wiley.
Uncontrolled Keywords:	Debaryomyces hansenii; biphosphate nucleotidase; HAL2; salt tolerance
Subjects:	Q Science > QR Microbiology
Depositing User:	Dr. K.P.S.Sengar
Date Deposited:	08 Jan 2012 05:40
Last Modified:	28 Mar 2012 10:06
URI:	http://crdd.osdd.net/open/id/eprint/177

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