Function-based selection and characterization of base-pair polymorphisms in a promoter of Escherichia coli RNA polymerase-sigma(70)

Citation
J. Xu et al., Function-based selection and characterization of base-pair polymorphisms in a promoter of Escherichia coli RNA polymerase-sigma(70), J BACT, 183(9), 2001, pp. 2866-2873
Citations number
37
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
JOURNAL OF BACTERIOLOGY
ISSN journal
0021-9193 → ACNP
Volume
183
Issue
9
Year of publication
2001
Pages
2866 - 2873
Database
ISI
SICI code
0021-9193(200105)183:9<2866:FSACOB>2.0.ZU;2-O
Abstract
We performed two sets of in vitro selections to dissect the role of the -10 base sequence in determining the rate and efficiency with which Escherichi a coli RNA polymerase-sigma (70) forms stable complexes with a promoter, We identified sequences that (i) rapidly form heparin-resistant complexes wit h RNA polymerase or (ii) form heparin-resistant complexes at very low RNA p olymerase concentrations. The sequences selected under the two conditions d iffer from each other and from the consensus -10 sequence, The selected pro moters have the expected enhanced binding and kinetic properties and are fu nctionally better than the consensus promoter sequence in directing RNA syn thesis in vitro. Detailed analysis of the selected promoter functions shows that each step in this multistep pathway may have different sequence requi rements, meaning that the sequence of a strong promoter does not contain th e optimal sequence for each step but instead is a compromise sequence that allows all steps to proceed with minimal constraint.