Evolutionary divergence of the Citrobacter freundii tryptophan operon regulatory region: comparison with other enteric bacteria
Year: 1982
Type: article
Abstract: The regulatory region of the trp operon of Citrobacter freundii was sequenced and compared with the corresponding regions of other enteric bacteria. Significant differences were noted in the promoter region. These differences are presumably responsible for the weak expression of the cloned trp operon in Escherichia coli. The presumed operator region, although nonfunctional in E. coli, has dyad symmetry, but the sequence of the symmetrical region differs appreciably from those of operators that can be regulated by the E. coli trp repressor. The sequence of the trp leader region of C. freundii resembles that of other enteric bacteria, suggesting that the C. freundii operon is also regulated by attenuation. Comparison of the sequence of the initial portion of trpE with the homologous regions of E. coli and Salmonella typhimurium indicates that the three organisms probably are evolutionary equidistant.
Source: Journal of Bacteriology
Authors: M Blumenberg, C Yanofsky
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W1483333924