ISSN:
1617-4623
Keywords:
Heat shock proteins
;
Subunit assembly
;
Aggregation
;
RNA polymerase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Escherichia coli cells, carrying a rifampicin sensitive RNA polymerase β-subunit gene in the chromosome and a rifampicin resistant β-subunit gene placed under the control of a strong promoter in a multicopy plasmid, are unable to grow in the presence of rifampicin, despite the accumulation of large quantities of the resistant subunit. A major portion of the overproduced subunit is found in an insoluble form. Conditions known to induce the heat shock proteins (hsps), e.g. elevated temperature or the presence of ethanol in the growth medium, increase the amount of the plasmid-borne β-subunit which apparently assembles into active RNA polymerase and makes the plasmid bearing cells rifampicin resistant. Alternatively, plasmid-borne subunits assemble into RNA polymerase with low efficiency in rpoH mutant cells known to have reduced level of hsps. We suggest that the plasmid-borne subunit is poorly assembled into RNA polymerase and that hsps promote the assembly by interfering with β-subunit aggregation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00334392
