The proposed experiments are directed towards a molecular understanding of the specialized recombination events attributeable to the prokaryotic kanamycin resistance transposon Tn5 in E. coli and, more generally, to the understanidng of the evolution of antibiotic resistance transposons and their component genes. We will employ genetic and molecular approaches to: (19 generate a transposase gene (tnp)-1ac operon fusion in Tn5 and use it to learn how tnp transcription is regulated, obtain tnp nonsense mutants, and produce large quantities of transposase protein in vivo: (2) determine conditions under which the Tn5 encoded transpospase limits the rate of transposition in vivo: (3) detect transposase activity in vitro; (4) test current models of transposon stimulated deletion formation; (5) examine the structural, physiological and genetic factors which control the rate of Tn5 excision; (6) learn whether components of Tn5 retain the capacity for transposition by themselves, in the absence of intact Tn5: and (7) detect and characterize new aminoglycoside resistance transposons in Gram negative clinical isolates.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM037138-10
Application #
3292213
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1985-12-01
Project End
1990-11-30
Budget Start
1986-12-01
Budget End
1987-11-30
Support Year
10
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Washington University
Department
Type
Schools of Medicine
DUNS #
062761671
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Krishnan, B R; Kersulyte, D; Brikun, I et al. (1993) Transposon-based and polymerase chain reaction-based sequencing of DNAs cloned in lambda phage. Methods Enzymol 218:258-79
Neuwald, A F; Krishnan, B R; Brikun, I et al. (1992) cysQ, a gene needed for cysteine synthesis in Escherichia coli K-12 only during aerobic growth. J Bacteriol 174:415-25
Kersulyte, D; Krishnan, B R; Berg, D E (1992) Nonrandom orientation of transposon Tn5supF insertions in phage lambda. Gene 114:91-6
Phadnis, S H; Kulakauskas, S; Krishnan, B R et al. (1991) Transposon Tn5supF-based reverse genetic method for mutational analysis of Escherichia coli with DNAs cloned in lambda phage. J Bacteriol 173:896-9
Weston-Hafer, K; Berg, D E (1991) Limits to the role of palindromy in deletion formation. J Bacteriol 173:315-8
Krishnan, B R; Kersulyte, D; Brikun, I et al. (1991) Direct and crossover PCR amplification to facilitate Tn5supF-based sequencing of lambda phage clones. Nucleic Acids Res 19:6177-82
Dodson, K W; Berg, D E (1991) A sequence at the inside end of IS50 down regulates transposition. Plasmid 25:145-8
Weston-Hafer, K; Berg, D E (1991) Deletions in plasmid pBR322: replication slippage involving leading and lagging strands. Genetics 127:649-55
Lodge, J K; Weston-Hafer, K; Berg, D E (1991) Tn5 insertion specificity is not influenced by IS50 end sequences in target DNA. Mol Gen Genet 228:312-5
Kulakauskas, S; Wikstrom, P M; Berg, D E (1991) Efficient introduction of cloned mutant alleles into the Escherichia coli chromosome. J Bacteriol 173:2633-8

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