ISSN:
1617-4623
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The Escherichia coli K12 strain derivative MX 109, carries the strA938 mutant allele. It was isolated as a spontaneous high-level streptomycin resistant mutant, having the additional characteristic of growing slowly at a wide range of temperatures. Thus far, these two phenotypic characteristics have not been genetically segregated and, probably, are the result of a single mutational event at the strA locus. A number of pleiotropic alterations are also observed in cells of MX109 when compared two wild type cells, very likely as a consequence of the expression of the strA938 mutant allele. These are, i) decrease in their polysome content, ii) increase in their RNA to protein ratio, iii) increase in the density of the cells, iv) accumulation during growth of 30S and 50S ribosomal precursors, and v) low efficiency of their ribosomes to support polypeptide synthesis in vitro. Most of these effects are observed at 37° C but are more marked if cells or extracts are incubated at 20° C. These observations point to a reduced efficiency for protein synthesis of the ribosomes of MX109, as the primary effect exerted by the 30S-protein product of the strA938 mutant allele.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00333184
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