Gin mutants that can be suppressed by a Fis-independent mutation

Spaeny-Dekking, L; Schlicher, E; Franken, Kees L. M. C.; Putte, Pieter van de; Goosen, Nora

doi:10.1128/jb.177.1.222-228.1995

Cited by 8 publications

(5 citation statements)

References 35 publications

(40 reference statements)

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“…The basis for this hypothesis is the following: (1) It was shown that the proposed dimer interface of invertase is critical to the interplay between Fis and Hin; detergents which weaken this interface increase the DNA cleavage rate of Hin [25]. This is consistent with the observation that all the reported Fisindependent invertase mutations [25,[28][29][30][31] are at or very near this interface. (2) The bottom of this invertase dimer interface is not only symmetry-unique for a 1:1 Fis dimer/ invertase dimer recognition, but may also serve as a strategic area of contact for Fis, since perturbation there can be amplified to result in structural alteration at both the dimer interface and the DNA cleaving sites; the latter may be transmitted through a 'scissors-like' motion involving the central ß-sheet which had been shown to possess unusual flexibilities [32].…”

Section: A Hypothesis For Fis-invertase Recognitionsupporting

confidence: 70%

A model for Fis N‐terminus and Fis‐invertase recognition

Tzou

Hwang

1997

FEBS Letters

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In this modeling, we show that the elusive Fis Nterminus involved in invertase-mediated site-specific DNA inversion is, by all indications, a hinged flapping loop. The prediction is based on a combined sequence and secondary structure alignment against known structures of protein segments, as well as a tetrapeptide fragment observed crystallographically. Its validity is strongly supported by the ability to interpret consistently the available mutagenesis data pertaining to this region including, especially, a series of deletion mutants which until this work had been a puzzle in the search for structural explanations. A model for Fis-invertase recognition is also proposed.

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Section: A Hypothesis For Fis-invertase Recognitionsupporting

confidence: 70%

A model for Fis N‐terminus and Fis‐invertase recognition

Tzou

Hwang

1997

FEBS Letters

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“…To further characterize the ability of the repressor to oligomerize, chemical cross-linking experiments were performed using both DEB and BS 3 , which covalently link lysine residues in vitro (Spaeny-Dekking et al, 1995;Staros et al, 1987). The linking carbon chain of these molecules is 4 and 11.4 Å, respectively.…”

Section: Interactions Between Repressor and The Entire Mu Operatormentioning

confidence: 99%

Interactions between the Repressor and the Early Operator Region of Bacteriophage Mu

Rousseau¹,

Bétermier²,

Chandler

et al. 1996

Journal of Biological Chemistry

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The repressor of bacteriophage Mu, c, binds to three operator sites, O1, O2, and O3, overlapping two divergent promoters, which regulate the lytic and lysogenic pathways. Its binding to this operator region generates several complexes, which were analyzed by DNase I protection experiments. We demonstrate that c first binds to two 11-base pair partially repeated sequences in O2 that could represent "core" binding sites for the repressor. This initial interaction serves as an organizer of a more complex nucleoprotein structure in which O2, O1, and O3 become successively occupied. The quaternary structure of the repressor was also investigated. Size exclusion chromatography and protein-protein crosslinking experiments with chemicals that possess linking arms of various lengths indicate that the repressor oligomerizes in solution. A model is proposed describing the successive interactions of c with the operator sites O2, O1, and O3 leading to the elaboration of a higher order structure in which the early lytic functions are repressed.The repressor, c, of the temperate bacteriophage Mu controls the choice between lysogeny and lytic development. The decision is exercised at the level of transcription by binding of c to the early operator region located about 1 kilobase from the left end of the phage genome ( Fig. 1). This operator is contained within a 200-bp 1 region composed of two divergent promoters (Pe and Pc) and three operator sequences, O1, O2, and O3. These have been defined by DNase I protection of the region by the repressor (Krause et al., 1983(Krause et al., , 1986Alazard et al., 1992;Goosen et al., 1984). Binding of c to O1 and O2 appears to occur simultaneously at low repressor concentrations and prevents the initiation of transcription at the early promoter Pe. Binding to O3, which requires higher concentrations of c, inhibits transcription of the c gene from the Pc promoter (Goosen et al., 1984;Alazard et al., 1992). A binding site for integration host factor (IHF) is located between O1 and O2. This DNA-binding protein bends DNA and promotes the formation of looped structures (Craig and Nash, 1984;Gamas et al., 1987;Prentki et al., 1987;Stenzel et al., 1987;Robertson et al., 1988;Thompson et al., 1988). IHF plays a complex role in the regulation of the early functions of Mu. It has been demonstrated that it stimulates transcription from Pe, favoring lytic growth (Krause et al., 1986), possibly by direct interaction between bound IHF and RNA polymerase (Goosen and . On the other hand, IHF stabilizes the interaction among the repressor and O1 and O2 and allows the establishment and the maintenance of lysogeny (Vogel et al., 1991;Alazard et al., 1992;Gama et al., 1992;Bétermier et al., 1995).Previous results (Alazard et al., 1992) show that the interaction of c with a linear operator fragment leads to the formation of at least five high molecular weight DNA-protein complexes, which can be separated using gel retardation techniques. The complexes with lower apparent molecular weight can be chased successiv...

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“…9). Conformational changes within the dimer interface that are induced by Fis have also been proposed for Gin, based on the properties of mutations within the region [12,36].…”

Section: Amino-acid Substitutions Within the Dimer Interface Have Different Effects On Catalysismentioning

confidence: 99%