Temperature-sensitive catabolite activator protein in Escherichia coli BUG6

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• The BUG6 mutant displays temperature-sensitive cell division, forming filaments at non-permissive temperatures.
• Synthesis of maltose and galactose transport systems is also temperature-sensitive in BUG6.

Purpose of the Study:

• To investigate the genetic basis of temperature-sensitive cell division and maltose transport in the BUG6 mutant.
• To determine the regulatory mechanisms controlling maltose transport gene expression.

Main Methods:

• Utilized operon and protein fusions of maltose transport genes with lacZ.
• Employed P1-mediated transduction to map temperature-sensitive mutations.
• Complemented the crp mutation using a hybrid plasmid.

Main Results:

• Identified two independent temperature-sensitive mutations in BUG6.
• One mutation, near the fts-envA region, causes temperature-sensitive cell division.
• The second mutation, located in the crp gene, is responsible for temperature-sensitive maltose transport system synthesis at the transcriptional level.
• The crp mutation significantly blocks maltose transport gene transcription but has minimal effect on lac operon transcription.

Conclusions:

• The crp gene mutation is critical for the temperature-sensitive regulation of maltose transport.
• BUG6 provides a model for studying the interplay between cell division and nutrient transport regulation in Escherichia coli.