YML003w, a gene of unknown function, is required for spontaneous and UV-induced mutations

YML003w. a gene of unknown function is defined on a truncated gene in S288C. The next annotated ORF, YML002w, is therefore not expressed in S288C. Previous studies suggest that these two genes is a large ORF in wild type strains named VRL1. Based on our previous study, we speculate YML003w might be involved in a DNA repair process and its null mutant is sensitive to DNA damage agents. No spontaneous or UV induced mutations are seen in the deletion of YML003w, while overexpression of YML003w results in an increase in spontaneous and UV-induced mutations compared to the wild type frequencies. We then created a series of double deletion strains with yml003w- and other DNA repair related genes. The deletion of YML003w results in loss of spontaneous mutations in most deletions, with the exception of rad5- and mms2-. UV sensitivity of many of these mutants is reversed in the absence of YML003w. Our findings suggest that YML003w plays an important role in mutagenesis and UV sensitivity and potentially interacts with Rad5 mediated pathways.