Molecular cloning of Drosophila mus308, a gene involved in DNA cross-link repair with homology to prokaryotic DNA polymerase I genes.
Mutations in the Drosophila mus308 gene confer specific hypersensitivity to DNA-cross-linking agents as a consequence of defects in DNA repair. The mus308 gene is shown here to encode a 229-kDa protein in which the amino-terminal domain contains the seven conserved motifs characteristic of DNA and RNA helicases and the carboxy-terminal domain shares over 55% sequence similarity with the polymerase domains of prokaryotic DNA polymerase I-like enzymes. This is the first reported member of this family of DNA polymerases in a eukaryotic organism, as well as the first example of a single polypeptide with homology to both DNA polymerase and helicase motifs. Identification of a closely related gene in the genome of Caenorhabditis elegans suggests that this novel polypeptide may play an evolutionarily conserved role in the repair of DNA damage in eukaryotic organisms.
Harris
P V
PV
Section of Molecular and Cellular Biology, University of California, Davis 95616, USA.
Mazina
O M
OM
Leonhardt
E A
EA
Case
R B
RB
Boyd
J B
JB
Burtis
K C
KC
D000595:Amino Acid Sequence; D000818:Animals; D001407:Bacillus / Q000201:enzymology; D017173:Caenorhabditis elegans / Q000201:enzymology / Q000235:genetics; D003001:Cloning, Molecular; D004265:DNA Helicases / Q000737:chemistry; D004256:DNA Polymerase I / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D004260:DNA Repair; D045643:DNA Repair Enzymes; D004259:DNA-Directed DNA Polymerase; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology; D017344:Genes, Insect; D008961:Models, Structural; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D017386:Sequence Homology, Amino Acid; D013296:Streptococcus pneumoniae / Q000201:enzymology; D000097462:DNA Polymerase theta
D004265:DNA Helicases; D004256:DNA Polymerase I; D045643:DNA Repair Enzymes; D004259:DNA-Directed DNA Polymerase; D029721:Drosophila Proteins; D011994:Recombinant Proteins; C101782:DNApol-theta protein, Drosophila; D000097462:DNA Polymerase theta