Substrate inhibition of uracil phosphoribosyltransferase (UPRT) in distinct microbial species and its implications in the phenotype of uracil auxotrophs

Abstract

Background: Unlike the established practice, the supply of exogenous uracil cannot fully rescue uracil auxotrophy in Ura- mutants of some species of industrial and/or medical significance (e.g. Ashbya gossypii, Candida guilliermondii, C. albicans, Leishmania donovani), which require uridine for proper growth [1-4]. Here we reveal the molecular mechanism underlying this phenotype in A. gossypii and disclose common features with protozoan parasites and other flavinogenic/pathogenic fungi.