Abstract

rnh (formerly sdrA) mutants of Escherichia coli K-12 are devoid of RNase H activity. These mutants are capable of initiating repeated rounds of DNA replication in the absence of protein synthesis (stable DNA replication). The rnh mutants can despense with the normally required dnaA+ protein and to oriC site, the origin of DNA replication. In the absence of RNase H activity and the oriC site, at least four regions of the E. coli chromosome can be used as new origins (oriK) of DNA replication. Initiation of DNA replication of oriK requires the recA+ protein. In this application, genetic and biochemical experiments are propossed to elucidate the roles of RNase H and recombination functions (recA+) in the initiation of DNA replication. Also proposed are experiments to examine a possible involvement of stable DNA replication in the mutagenesis process that occurs as a result of cellular response to DNA damage. Efforts will also be made to isolate mutants in which initiation of DNA replication at oriC can occur in the absence of concomitant protein synthesis.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM022092-11
Application #
3270926
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1978-12-01
Project End
1990-02-28
Budget Start
1986-03-01
Budget End
1987-02-28
Support Year
11
Fiscal Year
1986
Total Cost
Indirect Cost

  Institution

Name
University of New Mexico
Department
Type
Schools of Arts and Sciences
DUNS #
829868723
City
Albuquerque
State
NM
Country
United States
Zip Code
87131

  Publications

Kasahara, M; Clikeman, J A; Bates, D B et al. (2000) RecA protein-dependent R-loop formation in vitro. Genes Dev 14:360-5
Asai, T; Bates, D B; Boye, E et al. (1998) Are minichromosomes valid model systems for DNA replication control? Lessons learned from Escherichia coli. Mol Microbiol 29:671-5
Bates, D B; Boye, E; Asai, T et al. (1997) The absence of effect of gid or mioC transcription on the initiation of chromosomal replication in Escherichia coli. Proc Natl Acad Sci U S A 94:12497-502
Kogoma, T; Maldonado, R R (1997) DNA polymerase I in constitutive stable DNA replication in Escherichia coli. J Bacteriol 179:2109-15
Kogoma, T (1997) Stable DNA replication: interplay between DNA replication, homologous recombination, and transcription. Microbiol Mol Biol Rev 61:212-38
Hong, X; Cadwell, G W; Kogoma, T (1996) Activation of stable DNA replication in rapidly growing Escherichia coli at the time of entry to stationary phase. Mol Microbiol 21:953-61
Kogoma, T; Cadwell, G W; Barnard, K G et al. (1996) The DNA replication priming protein, PriA, is required for homologous recombination and double-strand break repair. J Bacteriol 178:1258-64
Bates, D B; Asai, T; Cao, Y et al. (1995) The DnaA box R4 in the minimal oriC is dispensable for initiation of Escherichia coli chromosome replication. Nucleic Acids Res 23:3119-25
Hong, X; Cadwell, G W; Kogoma, T (1995) Escherichia coli RecG and RecA proteins in R-loop formation. EMBO J 14:2385-92
Cao, Y; Kogoma, T (1995) The mechanism of recA polA lethality: suppression by RecA-independent recombination repair activated by the lexA(Def) mutation in Escherichia coli. Genetics 139:1483-94

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