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Transcription regulation of the Escherichia coli pcnB gene coding for poly(A) polymerase I: roles of ppGpp, DksA and sigma factors

Nadratowska-Wesołowska, Beata and Słomińska-Wojewódzka, Monika and Łyżeń, Robert and Węgrzyn, Alicja and Szalewska-Pałasz, Agnieszka and Węgrzyn, Grzegorz (2010) Transcription regulation of the Escherichia coli pcnB gene coding for poly(A) polymerase I: roles of ppGpp, DksA and sigma factors. Molecular Genetics and Genomics, 284 . pp. 289-305.

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Abstract

Poly(A) polymerase I (PAP I), encoded by the pcnB gene, is a major enzyme responsible for RNA polyadenylation in Escherichia coli, a process involved in the global control of gene expression in this bacterium through inXuencing the rate of transcript degradation. Recent studies have suggested a complicated regulation of pcnB expression, including a complex promoter region, a control at the level of translation initiation and dependence on bacterial growth rate. In this report, studies on transcription regulation of the pcnB gene are described. Results of in vivo and in vitro experiments indicated that (a) there are three �70-dependent (p1, pB, and p2) and two �S-dependent (pS1 and pS2) promoters of the pcnB gene, (b) guanosine tetraphosphate (ppGpp) and DksA directly inhibit transcription from pB, pS1 and pS2, and (c) pB activity is drastically impaired at the stationary phase of growth. These results indicate that regulation of the pcnB gene transcription is a complex process, which involves several factors acting to ensure precise control of PAP I production. Moreover, inhibition of activities of pS1 and pS2 by ppGpp and DksA suggests that regulation of transcription from promoters requiring alternative � factors by these eVectors of the stringent response might occur according to both passive and active models.

Item Type:Article
Subjects:Q Science > QH Natural history > QH301 Biology
Q Science > QH Natural history > QH426 Genetics
Q Science > QR Microbiology
Divisions:Laboratory of Molecular Biology (in Gdansk)
ID Code:251
Deposited By: Prof. Magdalena Gabig-Cimińska
Deposited On:29 Nov 2012 14:53
Last Modified:09 Jan 2013 09:46

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