» Articles » PMID: 3045090

Regulation of DNA Superhelicity by RpoB Mutations That Suppress Defective Rho-mediated Transcription Termination in Escherichia Coli

Overview
Journal J Bacteriol
Specialty Microbiology
Date 1988 Sep 1
PMID 3045090
Citations 10
Authors
Affiliations
Soon will be listed here.
Abstract

The highly defective rho-15 mutant of Escherichia coli produces plasmid DNA that is 22% less negatively supercoiled than DNA from an isogenic wild-type strain (J. S. Fassler, G. F. Arnold, and I. Tessman, Mol. Gen. Genet. 204:424-429, 1986). We extended our measurements of plasmid superhelicity to additional rho mutants and to strains containing mutations that suppress rho transcription termination defects; the suppressor mutations were in the rpoB and the rho genes. The superhelicity of plasmid DNA was reduced by 11 and 10%, respectively, in the rho-702 and rho-201 mutants, both of which are less defective in Rho-mediated transcription termination than rho-15. Plasmid superhelicity was restored in all the suppressed rho mutants; in one rpoB mutant, plasmid DNA was even more negatively supercoiled than in rpoB+ cells, whether in a rho+ or rho mutant background. Suppression of rho mutants enabled them to maintain plasmids that could not be maintained in the mutants in the absence of the suppressor mutations. The results indicate that in addition to DNA gyrase, topoisomerase I, and Rho, RNA polymerase is also a determinant of DNA superhelicity, and its effect is modified by the Rho protein. We propose that Rho may increase the degree of DNA unwinding by the transcription complex, possibly at transcription termination sites.

Citing Articles

Mastering the control of the Rho transcription factor for biotechnological applications.

Villa T, Abril A, Sanchez-Perez A Appl Microbiol Biotechnol. 2021; 105(10):4053-4071.

PMID: 33963893 DOI: 10.1007/s00253-021-11326-7.


A Screen for Suppressors Reveals a Key Role for a Connector Region of Termination Factor Rho.

Hu K, Artsimovitch I mBio. 2017; 8(3).

PMID: 28559482 PMC: 5449661. DOI: 10.1128/mBio.00753-17.


Structural coupling between RNA polymerase composition and DNA supercoiling in coordinating transcription: a global role for the omega subunit?.

Geertz M, Travers A, Mehandziska S, Sobetzko P, Chandra-Janga S, Shimamoto N mBio. 2011; 2(4).

PMID: 21810966 PMC: 3147163. DOI: 10.1128/mBio.00034-11.


Incompatibility of Escherichia coli rho mutants with plasmids is mediated by plasmid-specific transcription.

Li T, Panchenko Y, Drolet M, Liu L J Bacteriol. 1997; 179(18):5789-94.

PMID: 9294436 PMC: 179468. DOI: 10.1128/jb.179.18.5789-5794.1997.


Streptomycin- and rifampin-resistant mutants of Escherichia coli perturb F exclusion of bacteriophage T7 by affecting synthesis of the F plasmid protein PifA.

Schmidt C, Kemp P, Molineux I J Bacteriol. 1995; 177(6):1589-94.

PMID: 7883717 PMC: 176777. DOI: 10.1128/jb.177.6.1589-1594.1995.


References
1.
Puga A, Tessman I . Mechanism of transcription of bacteriophage S13. I. Dependence of messengerRNA synthesis on amount and configuration of DNA. J Mol Biol. 1973; 75(1):83-97. DOI: 10.1016/0022-2836(73)90530-5. View

2.
Funnell B, Baker T, Kornberg A . Complete enzymatic replication of plasmids containing the origin of the Escherichia coli chromosome. J Biol Chem. 1986; 261(12):5616-24. View

3.
Nene V, Glass R . Genetic studies on the beta subunit of Escherichia coli RNA polymerase. I. The effect of known, single amino acid substitutions in an essential protein. Mol Gen Genet. 1982; 188(3):399-404. DOI: 10.1007/BF00330040. View

4.
Goldberg A, Hurwitz J . Studies on termination of in vitro ribonucleic acid synthesis by rho factor. J Biol Chem. 1972; 247(17):5637-45. View

5.
Menzel R, Gellert M . Regulation of the genes for E. coli DNA gyrase: homeostatic control of DNA supercoiling. Cell. 1983; 34(1):105-13. DOI: 10.1016/0092-8674(83)90140-x. View