TheuvsIgene ofAspergillus nidulansrequired for UV-mutagenesis encodes a homolog to REV3, a subunit of the DNA polymerase ζ of yeast involved in translesion DNA synthesis

Abstract

Defects in the uvsI gene of Aspergillus nidulans resulted in high UV sensitivity and reductions of spontaneous and UV-induced reversion of certain alleles. uvsI;uvsA double mutants exhibited high methyl methane sulfonate (MMS)-sensitivity in contrast to the slight sensitivity of the component single mutants. Using such a double mutant as recipient, a clone complementing uvsI501 has been isolated from a chromosome III specific library. The deduced amino acid sequence from the 1.1-kb sequenced region, a part of the 5.2-kb DNA fragment showing uvsI-complementing activity, had a 62% identity with REV3 of yeast. Disruptants of the cloned gene demonstrated the same level of sensitivity to UV light as uvsI and failed to complement uvsI501 in heterozygous diploids.