Characterization of the mycobacterial NER system reveals novel functions of the uvrD1 helicase.
In this study, we investigated the role of the nucleotide excision repair (NER) pathway in mycobacterial DNA repair. Mycobacterium smegmatis lacking the NER excinuclease component uvrB or the helicase uvrD1 gene and a double knockout lacking both genes were constructed, and their sensitivities to a series of DNA-damaging agents were analyzed. As anticipated, the mycobacterial NER system was shown to be involved in the processing of bulky DNA adducts and interstrand cross-links. In addition, it could be shown to exert a protective effect against oxidizing and nitrosating agents. Interestingly, inactivation of uvrB and uvrD1 significantly increased marker integration frequencies in gene conversion assays. This implies that in mycobacteria (which lack the postreplicative mismatch repair system) NER, and particularly the UvrD1 helicase, is involved in the processing of a subset of recombination-associated mismatches.
Güthlein
Carolin
C
Institut für Medizinische Mikrobiologie, University of Zurich, Gloriastrasse 30/32, CH-8006, Zurich, Switzerland.
Wanner
Roger M
RM
Sander
Peter
P
Davis
Elaine O
EO
Bosshard
Martin
M
Jiricny
Josef
J
Böttger
Erik C
EC
Springer
Burkhard
B
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D020137:Base Pair Mismatch / Q000528:radiation effects; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair / Q000528:radiation effects; D005785:Gene Conversion / Q000528:radiation effects; D009154:Mutation / Q000528:radiation effects; D020102:Mycobacterium smegmatis / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D004265:DNA Helicases