The first zinc-binding domain of UvrA is not essential for UvrABC-mediated DNA excision repair.
Specific mutations in uvrA were introduced to analyze the role of the zinc-binding domains of the protein in DNA excision repair. Zinc-coordinating cysteines were substituted into non-coordinating serine or glycine residues. Mutations leading to changes in the second zinc-binding domain had a profound effect on UV survival in vivo; however these mutant proteins could not be isolated for in vitro analyses. Amino acid substitutions in the first zinc-binding domain had very little effect on UV survival in vivo. In vitro analyses showed that although this domain no longer coordinates zinc, ATPase activity, helicase activity, DNA binding, incision of damaged DNA and DNA repair synthesis appeared to be normal. Therefore it seems that the first zinc-binding domain of UvrA is not essential for DNA excision repair.
Visse
R
R
Department of Biochemistry, Gorlaeus Laboratories, Leiden University, The Netherlands.
de Ruijter
M
M
Ubbink
M
M
Brandsma
J A
JA
van de Putte
P
P
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D001665:Binding Sites; D003001:Cloning, Molecular; D004249:DNA Damage; D004265:DNA Helicases / Q000378:metabolism; D004260:DNA Repair; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D016297:Mutagenesis, Site-Directed; D015032:Zinc / Q000378:metabolism*
D000596:Amino Acids; D029968:Escherichia coli Proteins; D004706:Endodeoxyribonucleases; C036385:endodeoxyribonuclease uvrABC; D000251:Adenosine Triphosphatases; D004265:DNA Helicases; D015032:Zinc