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Updated: Oct 13, 2026

Site-Directed Mutagenesis for In Vitro and In Vivo Experiments Exemplified with RNA Interactions in Escherichia Coli
Published on: February 5, 2019
Interaction of sigma 70 with Escherichia coli RNA polymerase core enzyme studied by surface plasmon resonance
A L Ferguson1, A D Hughes, U Tufail
1Department of Biology, University of York, P.O. Box 373, Heslington, YO10 5YW, York, UK.
Abstract:
The interaction between the core form of bacterial RNA polymerases and sigma factors is essential for specific promoter recognition, and for coordinating the expression of different sets of genes in response to varying cellular needs. The interaction between Escherichia coli core RNA polymerase and sigma 70 has been investigated by surface plasmon resonance. The His-tagged form of sigma 70 factor was immobilised on a Ni2+-NTA chip for monitoring its interaction with core polymerase. The binding constant for the interaction was found to be 1.9x10(-7) M, and the dissociation rate constant for release of sigma from core, in the absence of DNA or transcription, was 4x10(-3) s(-1), corresponding to a half-life of about 200 s.
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