The yeast ISN1 (YOR155c) gene encodes a new type of IMP-specific 5'-nucleotidase.

ABSTRACT:

Background

The purine salvage enzyme inosine 5'-monophosphate (IMP)-specific 5'-nucleotidase catalyzes degradation of IMP to inosine. Although this enzymatic activity has been purified and characterized in Saccharomyces cerevisiae, the gene encoding IMP 5'-nucleotidase had not been identified.

Results

Mass spectrometry analysis of several peptides of this enzyme purified from yeast allowed identification of the corresponding gene as YOR155c, an open reading frame of unknown function, renamed ISN1. The deduced Isn1p sequence was clearly not homologous to 5'-nucleotidases from other species. However, significant similarities to Isn1p were found in proteins of unknown function from Neurospora crassa, Plasmodium falciparum and several yeast species. Knock-out of ISN1 resulted in

SUBMITTER: Itoh R 

PROVIDER: S-EPMC156364 | biostudies-literature | 2003 May

REPOSITORIES: biostudies-literature