Aberrant transcription in fit mutants of Escherichia coli and its alleviation by suppressor mutations.

ABSTRACT

Earlier work from this laboratory had identified, mapped and characterised an intragenic suppressor (fitA24) as well as an extragenic suppressor (fitB) for the temperature-sensitive transcription defective mutation fitA76 in Escherichia coli In this communication we report the results of experiments on RNA synthesis and decay of pulse labelled RNA in strains harbouring fit Α76, fitB, fitA24, fitA76-fitA24, fitA76-fitB mutation(s) as well as in the isogenic fitA+ fitB+ strain. Taken together with earlier results, this indicates that the fitA and fitB gene products could be involved in the expression of some classes of genes including genes coding for ribosomal proteins. The implications of these results for the in vivo control of transcription in Escherichia coli are discussed.