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Molecular characterization of the Salmonella typhimurium parE gene
1Department of Molecular Biology, Princeton University, NJ 08544.
Abstract:
The DNA sequence of the wild type S. typhimurium parE gene was determined. The predicted protein has 96.7% amino acid identity with the ParE protein of E.coli, but is 29 amino acids longer, due to an additional basepair in the 3' end of the S. typhimurium gene. Subclones of the S. typhimurium parE gene localized the sites of four heat sensitive mutations within parE. The parE206 and parE374 mutations are identical (Val67-Met) and lie in a highly conserved region corresponding to the ATP binding pocket of GyrB. Two additional heat sensitive mutations were sequenced and predict the following amino acid substitutions: parE377 (Gly399-Ser) and parE493 (Thr583-Pro). All of the heat sensitive mutations lie in regions with strong amino acid homology to GyrB.
Insights
The study sequenced the Salmonella typhimurium parE gene, finding it shares high similarity with E. coli
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- The parE gene is crucial for DNA replication and repair in bacteria.
- Understanding parE gene variations can reveal insights into bacterial resistance and evolution.
Purpose of the Study:
- To determine the DNA sequence of the wild type S. typhimurium parE gene.
- To identify and characterize heat-sensitive mutations within the S. typhimurium parE gene.
Main Methods:
- DNA sequencing of the S. typhimurium parE gene.
- Subcloning to localize mutation sites.
- Amino acid sequence analysis and comparison with E. coli GyrB.
Main Results:
- The S. typhimurium parE gene sequence was determined, showing 96.7% amino acid identity to E. coli ParE.
- Four heat-sensitive mutations were localized, with two (parE206 and parE374) resulting in Val67-Met substitution in a conserved ATP-binding region homologous to GyrB.
- Two additional mutations, parE377 (Gly399-Ser) and parE493 (Thr583-Pro), were identified in regions homologous to GyrB.
Conclusions:
- The identified mutations in S. typhimurium parE affect conserved regions homologous to E. coli GyrB.
- These findings contribute to understanding the structure-function relationship of bacterial topoisomerase genes and potential drug targets.