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Studies on Escherichia coli mutants which block bacteriophage morphogenesis
Progress in Clinical and Biological Research
|January 1, 1981
Summary
Researchers identified a second E. coli groE gene, groES, essential for bacteriophage lambda head assembly. Both groES and the previously known groEL gene are crucial for bacterial growth and phage development.
Area of Science:
- Microbiology
- Molecular Biology
- Bacteriology
Background:
- E. coli groE mutants were previously shown to impede lambda phage head morphogenesis.
- Some groE mutants exhibit temperature-sensitive growth defects or inhibit unrelated phage growth (T4, T5).
Purpose of the Study:
- To characterize the genetic and biochemical basis of E. coli groE mutants affecting lambda phage assembly.
- To identify and define a second gene within the groE locus.
Main Methods:
- Genetic analysis of lambda groE+ transducing phages and their mutant derivatives.
- Biochemical characterization of gene products and phage components.
Main Results:
- A second groE gene, designated groES, was identified and is distinct from the previously described groEL gene.
- The groES gene encodes a 15,000-Mr polypeptide.
- groES and groEL genes are closely linked.
- Mutants lacking functional groEL or groES exhibit similar high-temperature growth phenotypes.
- Lambda prohead composition remains unchanged in both groEL and groES mutants.
Conclusions:
- The E. coli groE locus comprises at least two genes: groEL and groES.
- Both groEL and groES are essential for bacterial growth and lambda phage morphogenesis.
- The groES gene product is a 15,000-Mr polypeptide involved in phage assembly.