CGC Bibliography Paper 5401

The Caenorhabditis elegans Y87G2A.14 Nudix hydrolase is a peroxisomal coenzyme A diphosphatase.

AbdelRaheim SR, McLennan AG

Medline:

11943069

Citation:

BMC Biochemistry 3: - 2002

Type:

ARTICLE

Genes:

Abstract:

Background: The number of Nudix hydrolase family members varies widely among different organisms. In order to understand the reasons for the particular spectrum possessed by a given organism, the substrate specificity and function of different family members must be established. Results: The Y87G2A.14 Nudix hydrolase gene product of Caenorhabditis elegans has been expressed as a thioredoxin fusion protein in Escherichia coli and shown to be a CoA diphosphatase with catalytic activity towards CoA and its derivatives. The products of CoA hydrolysis were 3',5'-ADP and 4'-phosphopantetheine with Km and kcat values of 220 muM and 13.8 s-1 respectively. CoAesters yielded 3',5'-ADP and the corresponding acyl-phosphopantetheine. Activity was optimal at pH 9.5 with 5 mM Mg2+ and fluoride was inhibitory with a Ki of 3 muM. The Y87G2A.14 gene product has a potential C-terminal tripeptide PTS1 peroxisomal targeting signal SKI. By fusing a Y87G2A.14cDNA to the C-terminus of yeast-enhanced green fluorescent protein, the enzyme appeared to be targeted to peroxisomes by the SKI signal when transfected into yeast cells. Deletion of SKI abolished specific targeting. Conclusions: The presence of related sequences with potential PTS1 or PTS2 peroxisomal targeting signals in other organisms suggests a conserved peroxisomal function for the CoA diphosphatase members of this group of Nudix hydrolases.