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. 1981 Feb;145(2):840–844. doi: 10.1128/jb.145.2.840-844.1981

sfrA and sfrB products of Escherichia coli K-12 are transcriptional control factors.

L Beutin, P A Manning, M Achtman, N Willetts
PMCID: PMC217187  PMID: 7007352

Abstract

The mechanisms whereby mutations in Escherichia coli K-12 genes sfrA and sfrB reduce expression of the transfer functions of sex factor F have been examined by assaying the levels of tra messenger ribonucleic acid and of tra proteins. The sfrA product was necessary for efficient transcription of the control gene traJ and, directly or indirectly, for transcription of the traY leads to Z operon. In the absence of sfrA, reduced levels of the traJ and traT proteins were observed in the outer membrane. The sfrB product was needed to prevent premature transcription at one or more rho-dependent termination sites. sfrB mutations also reduced synthesis of full-length lipopolysaccharide molecules, of several chromosomally determined outer membrane proteins, and of functional flagella. Thus, the sfrB product may act as an antiterminator in transcription of several operons encording cell envelope components.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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