microbiology, Vol 142, 505-515, Copyright © 1996 by Society for General Microbiology
nuvA, an Aspergillus nidulans gene involved in DNA repair and recombination, is a homologue of Saccharomyces cerevisiae RAD18 and Neurospora crassa uvs-2
L Iwanejko, C Cotton, G Jones, B Tomsett and P Strike
Department of Genetics and Microbiology, University of Liverpool, UK.
A 40 kb genomic clone and 2.3 kb EcoRI subclone that rescued the DNA repair
and recombination defects of the Aspergillus nidulans nuvA11 mutant were
isolated and the subclone sequenced. The subclone hybridized to a cosmid in
a chromosome-specific library confirming the assignment of nuvA to linkage
group IV and indicating its closeness to bimD. Amplification by PCR
clarified the relative positions of nuvA and bimD. A region identified
within the subclone, encoding a C3HC4 zinc finger motif, was used as a
probe to retrieve a cDNA clone. Sequencing of this clone showed that the
nuvA gene has an ORF of 1329 bp with two introns of 51 bp and 60 bp.
Expression of nuvA appears to be extremely low. The putative NUVA
polypeptide has two zinc finger motifs, a molecular mass of 48906 Da and
has 39% identity with the Neurospora crassa uvs-2 and 25% identity with the
Saccharomyces cerevisiae RAD18 translation products. Although mutations in
nuvA, uvs-2 and RAD18 produce similar phenotypes, only the nuvA11 mutation
affects meiotic recombination. A role for nuvA in both DNA repair and
genetic recombination is proposed.
