» Articles » PMID: 11087868

Mechanism for a Transcriptional Activator That Works at the Isomerization Step

Overview
Specialty Science
Date 2000 Nov 23
PMID 11087868
Citations 23
Authors
Affiliations
Soon will be listed here.
Abstract

Transcriptional activators in prokaryotes have been shown to stimulate different steps in the initiation process including the initial binding of RNA polymerase (RNAP) to the promoter and a postbinding step known as the isomerization step. Evidence suggests that activators that affect initial binding can work by a cooperative binding mechanism by making energetically favorable contacts with RNAP, but the mechanism by which activators affect the isomerization step is unclear. A well-studied example of an activator that normally exerts its effect exclusively on the isomerization step is the bacteriophage lambda cI protein (lambdacI), which has been shown genetically to interact with the C-terminal region of the final sigma(70) subunit of RNAP. We show here that the interaction between lambdacI and final sigma can stimulate transcription even when the relevant portion of final sigma is transplanted to another subunit of RNAP. This activation depends on the ability of lambdacI to stabilize the binding of the transplanted final sigma moiety to an ectopic -35 element. Based on these and previous findings, we discuss a simple model that explains how an activator's ability to stabilize the binding of an RNAP subdomain to the DNA can account for its effect on either the initial binding of RNAP to a promoter or the isomerization step.

Citing Articles

Bacillus subtilis: current and future modification strategies as a protein secreting factory.

Chen Y, Li M, Yan M, Chen Y, Saeed M, Ni Z World J Microbiol Biotechnol. 2024; 40(6):195.

PMID: 38722426 DOI: 10.1007/s11274-024-03997-x.


Minor Alterations in Core Promoter Element Positioning Reveal Functional Plasticity of a Bacterial Transcription Factor.

Chowdhury W, Satyshur K, Keck J, Kiley P mBio. 2021; 12(6):e0275321.

PMID: 34724814 PMC: 8561392. DOI: 10.1128/mBio.02753-21.


Structure and function of the mycobacterial transcription initiation complex with the essential regulator RbpA.

Hubin E, Fay A, Xu C, Bean J, Saecker R, Glickman M Elife. 2017; 6.

PMID: 28067618 PMC: 5302886. DOI: 10.7554/eLife.22520.


Local and global regulation of transcription initiation in bacteria.

Browning D, Busby S Nat Rev Microbiol. 2016; 14(10):638-50.

PMID: 27498839 DOI: 10.1038/nrmicro.2016.103.


Structural basis of transcription activation.

Feng Y, Zhang Y, Ebright R Science. 2016; 352(6291):1330-3.

PMID: 27284196 PMC: 4905602. DOI: 10.1126/science.aaf4417.


References
1.
Gardella T, Moyle H, Susskind M . A mutant Escherichia coli sigma 70 subunit of RNA polymerase with altered promoter specificity. J Mol Biol. 1989; 206(4):579-90. DOI: 10.1016/0022-2836(89)90567-6. View

2.
Rombel I, North A, Hwang I, Wyman C, Kustu S . The bacterial enhancer-binding protein NtrC as a molecular machine. Cold Spring Harb Symp Quant Biol. 1999; 63:157-66. DOI: 10.1101/sqb.1998.63.157. View

3.
Whipple F . Genetic analysis of prokaryotic and eukaryotic DNA-binding proteins in Escherichia coli. Nucleic Acids Res. 1998; 26(16):3700-6. PMC: 147751. DOI: 10.1093/nar/26.16.3700. View

4.
Landini P, Busby S . The Escherichia coli Ada protein can interact with two distinct determinants in the sigma70 subunit of RNA polymerase according to promoter architecture: identification of the target of Ada activation at the alkA promoter. J Bacteriol. 1999; 181(5):1524-9. PMC: 93542. DOI: 10.1128/JB.181.5.1524-1529.1999. View

5.
Kuldell N, Hochschild A . Amino acid substitutions in the -35 recognition motif of sigma 70 that result in defects in phage lambda repressor-stimulated transcription. J Bacteriol. 1994; 176(10):2991-8. PMC: 205456. DOI: 10.1128/jb.176.10.2991-2998.1994. View