Autoregulation of a bacterial σ factor explored by using segmental isotopic labeling and NMR
- 25 June 2002
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 99 (13) , 8536-8541
- https://doi.org/10.1073/pnas.132033899
Abstract
Bacterial σ factors combine with the catalytic core RNA polymerase to direct the process of transcription initiation through sequence-specific interactions with the −10 and −35 elements of promoter DNA. In the absence of core RNA polymerase, the DNA-binding function of σ is autoinhibited by its own N-terminal 90 amino acids (region 1.1), putatively by a direct interaction with conserved region 4.2, which binds the −35 promoter element. In the present work, this mechanism of autoinhibition was studied by using a combination of NMR spectroscopy and segmental isotopic labeling of a σ 70 -like subunit from Thermotoga maritima . Our data argue strongly against a high-affinity interaction between these two domains. Instead we suggest that autoinhibition of DNA binding occurs through an indirect steric and/or electrostatic mechanism. More generally, the present work illustrates the power of segmental isotopic labeling for probing molecular interactions in large proteins by NMR.Keywords
This publication has 24 references indexed in Scilit:
- Structure of the Bacterial RNA Polymerase Promoter Specificity σ SubunitMolecular Cell, 2002
- Development and Application of Expressed Protein LigationSynlett, 2001
- Synthesis of Native Proteins by Chemical LigationAnnual Review of Biochemistry, 2000
- Inhibition of Escherichia coli RNA polymerase by bacteriophage T4 AsiAJournal of Molecular Biology, 1998
- Regions of the Escherichia coli primary sigma factor σ70 that are involved in interaction with RNA polymerase core enzymeGenes to Cells, 1997
- Amino-terminal amino acids modulate sigma-factor DNA-binding activity.Genes & Development, 1993
- Polypeptides containing highly conserved regions of transcription initiation factor σ70 exhibit specificity of binding to promoter DNACell, 1992
- Altered promoter recognition by mutant forms of the σ70 subunit of Escherichia coli RNA polymeraseJournal of Molecular Biology, 1989
- A mutant Escherichia coli σ70 subunit of RNA polymerase with altered promoter specificityJournal of Molecular Biology, 1989
- Two functional domains conserved in major and alternate bacterial sigma factorsFEBS Letters, 1985