Nucleic Acids Research, 2003, Vol. 31, No. 19 5560-5567
© 2003 Oxford University Press
Characterization of AP lyase activities of Saccharomyces cerevisiae Ntg1p and Ntg2p: implications for biological function
1 Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, GA 30322, USA, 2 Department of Biochemistry, Rollins Research Center, 1510 Clifton Road, Emory University School of Medicine, Atlanta, GA 30322, USA and 3 Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA
*To whom correspondence should be addressed. Tel: +1 404 727 2659; Fax: +1 404 727 2618; Email: medpwd{at}emory.edu
Saccharomyces cerevisiae possesses two Escherichia coli endonuclease III homologs, NTG1 and NTG2, whose gene products function in the base excision repair pathway and initiate removal of a variety of oxidized pyrimidines from DNA. Although the glycosylase activity of these proteins has been well studied, the in vivo importance of the AP lyase activity has not been determined. Previous genetic studies have suggested that the AP lyase activities of Ntg1p and Ntg2p may be major contributors in the initial processing of abasic sites. We conducted a biochemical characterization of the AP lyase activities of Ntg1p and Ntg2p via a series of kinetic experiments. Such studies were designed to determine if Ntg1p and Ntg2p prefer specific bases located opposite abasic sites and whether these lesions are processed with a catalytic efficiency similar to Apn1p, the major hydrolytic AP endonuclease of yeast. Our results indicate that Ntg1p and Ntg2p are equally effective in processing four types of abasic site-containing substrates. Certain abasic site substrates were processed with greater catalytic efficiency than others, a situation similar to Apn1p processing of such substrates. These biochemical studies strongly support an important biological role for Ntg1p and Ntg2p in the initial processing of abasic sites and maintenance of genomic stability.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
P. Auerbach, R. A. O. Bennett, E. A. Bailey, H. E. Krokan, and B. Demple Mutagenic specificity of endogenously generated abasic sites in Saccharomyces cerevisiae chromosomal DNA PNAS, December 6, 2005; 102(49): 17711 - 17716. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. W. Kow, G. Bao, B. Minesinger, S. Jinks-Robertson, W. Siede, Y. L. Jiang, and M. M. Greenberg Mutagenic effects of abasic and oxidized abasic lesions in Saccharomyces cerevisiae Nucleic Acids Res., October 27, 2005; 33(19): 6196 - 6202. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. A. Doudican, B. Song, G. S. Shadel, and P. W. Doetsch Oxidative DNA Damage Causes Mitochondrial Genomic Instability in Saccharomyces cerevisiae Mol. Cell. Biol., June 15, 2005; 25(12): 5196 - 5204. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. B. Salmon, B. A. Evert, B. Song, and P. W. Doetsch Biological consequences of oxidative stress-induced DNA damage in Saccharomyces cerevisiae Nucleic Acids Res., July 14, 2004; 32(12): 3712 - 3723. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. A. Evert, T. B. Salmon, B. Song, L. Jingjing, W. Siede, and P. W. Doetsch Spontaneous DNA Damage in Saccharomyces cerevisiae Elicits Phenotypic Properties Similar to Cancer Cells J. Biol. Chem., May 21, 2004; 279(21): 22585 - 22594. [Abstract] [Full Text] [PDF] |
||||



