omp T: Escherichia coli K-12 structural gene for protein a (3b)

Area of Science:

• Microbiology
• Genetics
• Molecular Biology

Background:

• Escherichia coli K-12 is a widely studied bacterial model organism.
• Outer membrane protein a (OmpA) is a key structural component of the E. coli outer membrane.
• Strain UT400 is a previously characterized E. coli K-12 deletion mutant lacking OmpA.

Purpose of the Study:

• To identify and map the genetic locus responsible for the production of outer membrane protein a in E. coli.
• To confirm the location of the OmpA structural gene within the E. coli chromosome.

Main Methods:

• Hybridization experiments were performed between chromosomal DNA from E. coli strain UT400 and plasmid DNA (pGGC110) containing the OmpA structural gene.
• Genetic mapping techniques were employed to determine the chromosomal location.

Main Results:

• Chromosomal DNA from E. coli strain UT400 did not hybridize with plasmid DNA (pGGC110) carrying the OmpA structural gene.
• The genetic locus for OmpA was mapped to approximately 12.5 minutes on the E. coli chromosome.

Conclusions:

• The genetic locus for outer membrane protein a in E. coli K-12 is designated ompT.
• The ompT gene is located at approximately 12.5 min on the E. coli chromosome, confirming its chromosomal basis.