Mass spectrometry of Escherichia coli RNA polymerase: interactions of the core enzyme with sigma70 and Rsd protein. Academic Article uri icon

Overview

abstract

  • The E. coli RNA polymerase core enzyme is a multisubunit complex of 388,981 Da. To initiate transcription at promoters, the core enzyme associates with a sigma subunit to form holo RNA polymerase. Here we have used nanoflow electrospray mass spectrometry, coupled with tandem mass spectrometry, to probe the interaction of the RNA polymerase core enzyme with the most abundant sigma factor, sigma70. The results show remarkably well-resolved spectra for both the core and holo RNA polymerases. The regulator of sigma70, Rsd protein, has previously been identified as a protein that binds to free sigma70. We show that Rsd also interacts with core enzyme. In addition, by adding increasing amounts of Rsd, we show that sigma70 is displaced from holo RNA polymerase, resulting in complexes of Rsd with core and sigma70. The results argue for a model in which Rsd not only sequesters sigma70, but is also an effector of core RNA polymerase.

publication date

  • February 1, 2004

Research

keywords

  • DNA-Directed RNA Polymerases
  • Escherichia coli
  • Escherichia coli Proteins
  • Repressor Proteins
  • Sigma Factor

Identity

Scopus Document Identifier

  • 1242351231

Digital Object Identifier (DOI)

  • 10.1016/j.str.2004.01.007

PubMed ID

  • 14962387

Additional Document Info

volume

  • 12

issue

  • 2