Effects of forespore-specific overexpression of apurinic/apyrimidinic endonuclease Nfo on the DNA-damage resistance properties of Bacillus subtilis spores.
The effects of overexpression of the apurinic/apyrimidinic DNA endonuclease Nfo on wet and dry heat and UV-C (254 nm) resistance of Bacillus subtilis spores with or without alpha/beta-type small, acid-soluble spore proteins (SASP) were determined. Results revealed that overexpression of Nfo > or =50-fold in spores increased the wet heat resistance of exoA nfo B. subtilis spores (termed alpha(-)beta(-)) that lack most alpha/beta-type SASP, but had no effect on these spores' UV-C resistance. Nfo overexpression also increased these spores' dry heat resistance, and to levels slightly greater than that of wild-type spores. These results are consistent: (1) with wet and dry heat (but not UV-C) generating abasic sites in alpha(-)beta(-) spore DNA; (2) with dry heat generating some of these lesions in spores that retain alpha/beta-type SASP; and (3) indicate that Nfo can repair these abasic lesions following spore germination.
Barraza-Salas
Marcelo
M
Department of Biology, Division of Natural and Exact Sciences, University of Guanajuato, Guanajuato, Mexico.
Ibarra-Rodríguez
Juan R
JR
Mellado
Silvia J
SJ
Salas-Pacheco
José M
JM
Setlow
Peter
P
Pedraza-Reyes
Mario
M
D001412:Bacillus subtilis / Q000201:enzymology / Q000528:radiation effects*; D004249:DNA Damage; D004260:DNA Repair; D004269:DNA, Bacterial / Q000528:radiation effects*; D004720:Endonucleases / Q000096:biosynthesis*; D015870:Gene Expression; D006358:Hot Temperature; D050296:Microbial Viability; D013171:Spores, Bacterial / Q000201:enzymology / Q000528:radiation effects*; D014466:Ultraviolet Rays
D004269:DNA, Bacterial; D004720:Endonucleases