期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1981
卷号:78
期号:11
页码:7024-7027
DOI:10.1073/pnas.78.11.7024
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:We have previously shown that some Escherichia coli [derivatives of strain HS432 (polA1, polB100, polC1026)] can replicate DNA at a restrictive temperature in the presence of a polCts mutation and that such revertants contain apparent DNA polymerase I activity. We demonstrate here that this strain of E. coli becomes temperature-resistant upon the introduction of a normal gene for DNA polymerase I or suppression of the polA1 nonsense mutation. Such temperature-resistant phenocopies become temperature-sensitive upon introduction of a temperature-sensitive DNA polymerase I gene. Our results confirm that DNA replication is DNA polymerase I-dependent in the temperature-resistant revertants, indicating that an alternative pathway of replication exists in E. coli. HS432 contains a transducible locus (which we term pcbA) that can support an alternate pathway in other E. coli strains, so the effect of suppression of polCts is a general one.