Work

Escherichia coli σ 70 senses sequence and conformation of the promoter spacer region

Year: 2011

Type: article

Abstract: In bacteria, promoter identification by RNA polymerase is mediated by a dissociable σ factor. The housekeeping σ(70) factor of Escherichia coli recognizes two well characterized DNA sequence elements, known as the '-10' and '-35' hexamers. These elements are separated by 'spacer' DNA, the sequence of which is generally considered unimportant. Here, we use a combination of bioinformatics, genetics and biochemistry to show that σ(70) can sense the sequence and conformation of the promoter spacer region. Our data illustrate how alterations in spacer region sequence can increase promoter activity. This stimulatory effect requires σ(70) side chain R451, which is located in close proximity to the non-template strand at promoter position -18. Conversely, R451 is not required to mediate transcriptional stimulation by improvement of the -10 element. Mutation of σ(70) residue R451, which is highly conserved, results in reduced growth rate, consistent with a central role in promoter recognition.

Source: Nucleic Acids Research

DOI: 10.1093/nar/gkr080

Authors: Shivani S. Singh, Athanasios Typas, Regine Hengge, David C. Grainger

Institutions: University of Warwick, Freie Universität Berlin

Language: English

Topic: Bacterial Genetics and Biotechnology

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $3,992

Funder: Wellcome Trust