ISSN:
1617-4623
Keywords:
Aspergillus nidulans
;
DNA repair
;
uvsH
;
RAD18
;
UVS-2
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract TheuvsH DNA repair gene ofAspergillus nidulans has been cloned by complementation of theuvsH77 mutation with a cosmid library containing genomic DNA inserts from a wild-type strain. Methylmethane sulfonate (MMS)-resistant transformants were obtained on medium containing 0.01% MMS, to whichuvsH mutants exhibit high sensitivity . Retransformation ofuvsH77 mutants with the rescued cosmids from the MMS-resistant transformants resulted in restoration of both UV and MMS resistance to wild-type levels. Nucleotide sequence analysis of the genomic DNA and cDNA of theuvsH gene shows that it has an open reading frame (ORF) of 1329 bp, interrupted by two introns of 51 and 61 bp. A 2.4 kb transcript of theuvsH gene was detected by Northern blot analysis. Primer extension analysis revealed that transcription starts at 31 by upstream from the translation initiation codon. This gene encodes a predicted polypeptide of 443 amino acids, which has two unique zinc finger motifs. The proposed polypeptide displays 39% identity to theNeurospora crassa UVS-2 protein and 24% identity to theSaccharomyces cerevisiae RAD18 protein. The sequence similarity is particularly high in three domains. One zinc finger (RING finger) motif is located in the first domain close to the N-terminus. The other zinc finger motif is in the second domain. In the third domain, the mutation sites in both theuvsH77 anduvsH304 alleles were identified. TheuvsH77 allele has three base changes, resulting in a Thr → Pro alteration at amino acid 267 and Glu → Len at 268. TheuvsH304 mutation is caused by one base change, resulting in an Asn →Asp alteration at amino acid 274.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02190798
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