The understanding of how gene expression is controlled is fundamental in elucidating the mechanisms involved in normal and abnormal cellular growth and differentiation. Recent developments indicate that a number of different regulatory circuits are operative in controlling individual bacterial operons and in integrating the products of these pathways into the general metabolism of the cell. These data suggest that these biosynthetic systems may be valuable models for discovering how gene expression is regulated in complex as well as simple organisms. With this in mind we wish to continue out study of the mechanisms involved in control of the ilvB operon in E. coli K-12. A variety of regulatory elements are operative in this system including multi- valent endproduct attenuation by multiple species of tRNA, guanosine 3', 5'-bispyrophosphate, cyclic AMP and integration host factor. Studies on the mechanism of the individual control systems as well as how these systems interact will be investigated both in vivo and in vitro. The sequence of the promoter-regulatory region has been determined, and cloned fragments will be used in transcription studies to confirm the sites and nature of the promoter and regulatory region. In vivo investigators will focus on hybridization experiments with radioactively labelled RNA and ilvB DNA fragment probes which have defined regions of the regulatory-promoter region. In addition, the mechanism and interactions of the various regulatory elements will be investigated in a coupled in vitro transcription-translation system.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM017152-18
Application #
3269066
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1977-09-01
Project End
1990-08-31
Budget Start
1986-09-01
Budget End
1987-08-31
Support Year
18
Fiscal Year
1986
Total Cost
Indirect Cost
Name
State University New York Stony Brook
Department
Type
Schools of Medicine
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794
Ramani, N; Hedeshian, M; Freundlich, M (1994) micF antisense RNA has a major role in osmoregulation of OmpF in Escherichia coli. J Bacteriol 176:5005-10
Sirko, A; Zehelein, E; Freundlich, M et al. (1993) Integration host factor is required for anaerobic pyruvate induction of pfl operon expression in Escherichia coli. J Bacteriol 175:5769-77
Huang, L; Tsui, P; Freundlich, M (1992) Positive and negative control of ompB transcription in Escherichia coli by cyclic AMP and the cyclic AMP receptor protein. J Bacteriol 174:664-70
Ramani, N; Huang, L; Freundlich, M (1992) In vitro interactions of integration host factor with the ompF promoter-regulatory region of Escherichia coli. Mol Gen Genet 231:248-55
Freundlich, M; Ramani, N; Mathew, E et al. (1992) The role of integration host factor in gene expression in Escherichia coli. Mol Microbiol 6:2557-63
Tsui, P; Huang, L; Freundlich, M (1991) Integration host factor binds specifically to multiple sites in the ompB promoter of Escherichia coli and inhibits transcription. J Bacteriol 173:5800-7
Huang, L; Tsui, P; Freundlich, M (1990) Integration host factor is a negative effector of in vivo and in vitro expression of ompC in Escherichia coli. J Bacteriol 172:5293-8
Tsui, P; Freundlich, M (1990) Integration host factor bends the DNA in the Escherichia coli ilvBN promoter region. Mol Gen Genet 223:349-52
Tsui, P; Freundlich, M (1988) Integration host factor binds specifically to sites in the ilvGMEDA operon in Escherichia coli. J Mol Biol 203:817-20
Tsui, P; Helu, V; Freundlich, M (1988) Altered osmoregulation of ompF in integration host factor mutants of Escherichia coli. J Bacteriol 170:4950-3

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