TY - JOUR
T1 - Molecular mechanism of base excision repair of uracil-containing DNA in yeast cell-free extracts
AU - Wang, Zhigang
AU - Wu, Xiaohua
AU - Friedberg, Errol C.
PY - 1997/9/19
Y1 - 1997/9/19
N2 - Base excision repair (BER) constitutes a ubiquitous excision repair mechanism, which is responsible for the removal of multiple types of damaged and inappropriate bases in DNA. We have employed a yeast cell-free system to examine the biochemical mechanism of the BER pathway in lower eukaryotes. Using uracil-containing DNA as a model substrate, we demonstrate that yeast BER requires Apn1 protein, an Escherichia coli endonuclease IV homolog. In extracts of an apn1 deletion mutant, the 5'-incision at AP (apurinic/apyrimidinic) sites is not detectable, supporting the notion that yeast contains only one major 5'-AP endonuclease. The processing of the 5'- deoxyribose phosphate moieties was found to be a rate-limiting step. During BER of uracil-containing DNA, repair patch sizes of 1-5 nucleotides were detected, with single nucleotide repair patches predominant.
AB - Base excision repair (BER) constitutes a ubiquitous excision repair mechanism, which is responsible for the removal of multiple types of damaged and inappropriate bases in DNA. We have employed a yeast cell-free system to examine the biochemical mechanism of the BER pathway in lower eukaryotes. Using uracil-containing DNA as a model substrate, we demonstrate that yeast BER requires Apn1 protein, an Escherichia coli endonuclease IV homolog. In extracts of an apn1 deletion mutant, the 5'-incision at AP (apurinic/apyrimidinic) sites is not detectable, supporting the notion that yeast contains only one major 5'-AP endonuclease. The processing of the 5'- deoxyribose phosphate moieties was found to be a rate-limiting step. During BER of uracil-containing DNA, repair patch sizes of 1-5 nucleotides were detected, with single nucleotide repair patches predominant.
UR - http://www.scopus.com/inward/record.url?scp=0030810636&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030810636&partnerID=8YFLogxK
U2 - 10.1074/jbc.272.38.24064
DO - 10.1074/jbc.272.38.24064
M3 - Article
C2 - 9295360
AN - SCOPUS:0030810636
SN - 0021-9258
VL - 272
SP - 24064
EP - 24071
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 38
ER -