Bidirectional transcription in the mom promoter region of bacteriophage Mu

Sun, Weiyong; Hattman, Stanley

doi:10.1006/jmbi.1998.2228

Cited by 12 publications

(14 citation statements)

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“…The T 6 run substitution mutations generated in momP1 also disrupt the A 6 tract in the complementary strand (Fig. 1), which is proposed to function as part of an UP element directing leftward transcription from the momP2 promoter (18). Hence, an alternate possibility for the increased activity of momP1 in tin7 and other T 6 run mutants could be due to weakening of the UP element of momP2.…”

Section: Dna Structure Analysis Of Tmentioning

confidence: 99%

“…Hence, it is not surprising that intricate mechanisms have been evolved for the regulation of mom expression at both the transcriptional and translational levels (16). Apart from these modes of regulation, recently, Sun and Hattman (18) have suggested another possible regulatory control over mom expression. It was suggested that the leftward transcription at the momP2 promoter ( Fig.…”

Section: Dna Structure Analysis Of Tmentioning

confidence: 99%

“…Instead it binds an overlapping, divergent promoter region, momP2, which brings about "leftward" transcription (18). The stretch of six A nucleotides complementary to the T 6 run appears to be part of an UP element for leftward transcription from momP2 (18).…”

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confidence: 99%

“…In one such (partially) C-independent mutant, tin7, there is a single-base change (T to G at position Ϫ14) that disrupts the T 6 run in the momP1 spacer region (17). Few explanations could account for the increased promoter activity of tin7 mutant: 1) T tract-mediated intrinsic DNA curvature is lost because of disruption of the T 6 run (to T 3 GT 2 ), resulting in RNAP binding to momP1; 2) because P1 and P2 are overlapping divergent promoters, weakening of the UP element of momP2 (18) may facilitate the binding and activity of RNAP at momP1; and 3) the T(Ϫ14) to G change converts momP1 to an extended Ϫ10 promoter (28). The present study is an attempt to delineate the role of the T 6 run in momP1 promoter activity.…”

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confidence: 99%

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Intrinsic DNA Distortion of the Bacteriophage MumomP1 Promoter Is a Negative Regulator of Its Transcription

Basak

Olsen

Hattman

et al. 2001

Journal of Biological Chemistry

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The momP1 promoter of the bacteriophage Mu mom operon is an example of a weak promoter. It contains a 19-base pair suboptimal spacer between the ؊35 (ACCACA) and ؊10 (TAGAAT) hexamers. Escherichia coli RNA polymerase is unable to bind to momP1 on its own. DNA distortion caused by the presence of a run of six T nucleotides overlapping the 5 end of the ؊10 element might prevent RNA polymerase from binding to momP1. To investigate the influence of the T 6 run on momP1 expression, defined substitution mutations were introduced by site-directed mutagenesis. In vitro probing experiments with copper phenanthroline ((OP) 2 Cu) and DNase I revealed distinct differences in cleavage patterns among the various mutants; in addition, compared with the wild type, the mutants showed an increase (variable) in momP1 promoter activity in vivo. Promoter strength analyses were in agreement with the ability of these mutants to form open complexes as well as to produce momP1-specific transcripts. No significant role is attributed to the overlapping and divergently organized promoter, momP2, in the expression of momP1 activity, as determined by promoter disruption analysis. These data support the view that an intrinsic DNA distortion in the spacer region of momP1 acts in cis as a negative element in mom operon transcription. This is a novel mechanism of regulation of toxic gene expression.

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Section: Dna Structure Analysis Of Tmentioning

confidence: 99%

Section: Dna Structure Analysis Of Tmentioning

confidence: 99%

mentioning

confidence: 99%

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confidence: 99%

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Intrinsic DNA Distortion of the Bacteriophage MumomP1 Promoter Is a Negative Regulator of Its Transcription

Basak

Olsen

Hattman

et al. 2001

Journal of Biological Chemistry

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“…But in the assay no appropriate molecular weight was used to substantiate that, a tetramer could bind. Subsequent gel-shift and footprinting studies done by Sun and Hattman (1998) showed that C exhibited strong co-operativity in binding consistent with the binding of a tetramer,(4) The present structure may be a intermediate stage and crystallization may have only captured a snapshot of the whole DNA binding process. (5) The last hypotheses is that this might be nothing but an artifact of crystallization.…”

Section: Discussionmentioning

confidence: 93%

DNA Binding Specificity of Mu Transcription Factor C and Crystallization of C : DNA Complex

Shanmugantham¹

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Unusual interaction of RNA polymerase with the bacteriophage Mu middle promoter P_m in the absence of its activator protein Mor

Howe

2014

MicrobiologyOpen

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The bacteriophage Mu Mor activator protein is absolutely required for transcription from the Mu middle promoter Pm. However, when RNA polymerase (RNAP) was incubated with Pm DNA in the absence of Mor, a band at promoter position −51 was hypersensitive to DNase I cleavage, demonstrating an interaction of RNAP with the promoter DNA. The hypersensitivity was similar at four different lengths of Pm DNA assayed from −62 to +10, −62 to +46, −96 to +10, and −96 to +46. The hypersensitivity occurred equally well at 5°C, 15°C, and 30°C, indicating that it did not require open complex formation, which only occurred at 30°C. The −51 hypersensitivity at 5°C and 15°C was eliminated by the addition of heparin, consistent with the possibility that it arose by formation of unstable closed complexes of RNAP bound to Pm DNA. Generation of the hypersensitive band required the complete RNAP with its αCTDs, but neither the αCTD nor intact α were sufficient for the interaction and resulting hypersensitivity. There was no correlation between the level of hypersensitivity observed in vitro and the level of Pm activity in vivo, as assayed by the Mor-dependent production of β-galactosidase from a Pm-lacZ fusion. In an “order of addition” experiment, preincubation of Pm DNA with Mor followed by addition of RNAP led to the fastest open complex formation, whereas preincubation of Pm DNA with RNAP gave the slowest. These results support the conclusion that Mor recruits RNAP to Pm rather than reposition a prebound RNAP, as occurs for C-dependent repositioning of RNAP at the Mu late promoter Pmom.

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Bidirectional transcription in the mom promoter region of bacteriophage Mu

Cited by 12 publications

References 53 publications

Intrinsic DNA Distortion of the Bacteriophage MumomP1 Promoter Is a Negative Regulator of Its Transcription

Intrinsic DNA Distortion of the Bacteriophage MumomP1 Promoter Is a Negative Regulator of Its Transcription

DNA Binding Specificity of Mu Transcription Factor C and Crystallization of C : DNA Complex

Unusual interaction of RNA polymerase with the bacteriophage Mu middle promoter P_m in the absence of its activator protein Mor

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Bidirectional transcription in the mom promoter region of bacteriophage Mu

Cited by 12 publications

References 53 publications

Intrinsic DNA Distortion of the Bacteriophage MumomP1 Promoter Is a Negative Regulator of Its Transcription

Intrinsic DNA Distortion of the Bacteriophage MumomP1 Promoter Is a Negative Regulator of Its Transcription

DNA Binding Specificity of Mu Transcription Factor C and Crystallization of C : DNA Complex

Unusual interaction of RNA polymerase with the bacteriophage Mu middle promoter Pm in the absence of its activator protein Mor

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Unusual interaction of RNA polymerase with the bacteriophage Mu middle promoter P_m in the absence of its activator protein Mor