Localized conversion at the crossover sequences in the site-specific DNA inversion system of bacteriophage P1

Iida, Shigeru; Hiestand-Nauer, Rosemarie

doi:10.1016/0092-8674(86)90539-8

Cited by 41 publications

(28 citation statements)

References 19 publications

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“…When this sequence of the B segment was compared with those of other invertible segments, 23 (88.5%) of 26 bp for IRL and 24 (92.3%) of 26 bp for IRR were found to be identical to those of the G segment. Moreover, instead of the AA dinucleotide where recombination occurs (19,21,37), a 5' GA was observed in both IRs of the B segment, as reported for inv of the G segment (36). The homology with inv sequences from the H, C, and P segments is 53.9 to 80.8% for IRL and 53.9 to 84.6% for IRR (14).…”

Section: T P T T P T a R Q 6 T N N Tqmentioning

confidence: 58%

“…The other two ORFs are incomplete; one is on the 5' side of the cloned fragment and contains a 1,674-bp sequence which encodes 558 amino acids. The IRL within the sequence can separate it into a constant region (Bc; 1 to 654) and a variable region (Bv; 655 to 1674), provided that the crossover site is located within the central dinucleotide of the inv site (19,21,37). Another variable region (Bv'; 3727 to 2774), which may take the place of Bv when the B segment undergoes inversion, starts within the IRR present upstream of pinB, but no start codon or SD sequence was detected.…”

Section: Methodsmentioning

confidence: 99%

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Site-specific recombinase genes in three Shigella subgroups and nucleotide sequences of a pinB gene and an invertible B segment from Shigella boydii

1991

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Inversional switching systems in procaryotes are composed of an invertible DNA segment and a site-specific recombinase gene adjacent to or contained in the segment. Four related but functionally distinct systems have previously been characterized in detail: the Salmonella typhimurium H segment-hin gene (H-hin), phage Mu G-gin, phage P1 C-cin, and Escherichia coli e14 P-pin. In this article we report the isolation and characterization of three new recombinase genes: pinB, pinD, and defective pinF from Shigella boydii, ShigeUa dysenteriae, and Shigellaflexneri, respectively. The genes pinB and pinD were detected by the complementation of a hin mutation of Salmonella and were able to mediate inversion of the H, P, and C segments. pinB mediated H inversion as efficiently as the hin gene did and mediated C inversion with a frequency three orders of magnitude lower than that of the cin gene. pinD mediated inversion of H and P segments with frequencies ten times as high as those for the genes intrinsic to each segment and mediated C inversion with a frequency ten times lower than that for cin. Therefore, the pinB and pinD genes were inferred to be different from each other. The invertible B segment-pinB gene cloned from S. boydii is highly homologous to the G-gin in size, organization, and nucleotide sequence of open reading frames, but the 5' constant region outside the segment is quite different in size and predicted amino acid sequence. The B segment underwent inversion in the presence of hin, pin, or cin. The defective pinF gene is suggested to have-the same origin as P-pin on e14 by the restriction map of the fragment cloned from a Pin' transductant that was obtained in transduction from S. flexneri to E. coli Apin.

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Section: T P T T P T a R Q 6 T N N Tqmentioning

confidence: 58%

Section: Methodsmentioning

confidence: 99%

Site-specific recombinase genes in three Shigella subgroups and nucleotide sequences of a pinB gene and an invertible B segment from Shigella boydii

1991

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“…Previous studies using inversion tester plasmid pSHI301 showed that Cin recombinase can mediate inversion between a wild-type cix site and one of four quasi cix sites located within the transcription unit for AP resistance (17). Plasmid pFRZ31 was tested for its ability to undergo Cinmediated recombination in strain N100 by providing the Cin recombinase in trans.…”

Section: Resultsmentioning

confidence: 99%

“…E. coli N100 cells containing pFRZ31 were transformed with pPHU78 (13), thus providing Cin in trans, to determine if inversion occurs on pFRZ31 at the known cixQ3, cixQ4, cixQ5, and cixQ6 sites (17) or at other unknown cixQ sites. Following transformation, cells were plated onto MacConkey-Gal-AP-KM plates and grown at 37ЊC.…”

Section: Methodsmentioning

confidence: 99%

“…A cis-acting recombinational enhancer, sis(P1), located within the cin gene provides binding sites for E. coli Fis protein that increase the frequency of inversion 100-fold (12). Studies with inversion tester plasmids containing juxtaposed cixL and cixR crossover sites or a single cix site have shown that Cin-mediated inversion that results in two hybrid junction sites can occur infrequently between wild-type cix and secondary, or quasi, cix sites (cixQ) (16)(17)(18)(19)(20). The efficiency of this recombination is somewhat related to the degree of homology between the secondary crossover site and the consensus cix sequence.…”

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confidence: 99%

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Cin-mediated recombination at secondary crossover sites on the Escherichia coli chromosome

et al. 1995

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The Cin recombinase is known to mediate DNA inversion between two wild-type cix sites flanking genetic determinants for the host range of bacteriophage P1. Cin can also act with low frequency at secondary (or quasi) sites (designated cixQ) that have lower homology to either wild-type site. An inversion tester sequence able to reveal novel operon fusions was integrated into the Escherichia coli chromosome, and the Cin recombinase was provided in trans. Among a total of 13 Cin-mediated inversions studied, three different cixQ sites had been used. In two rearranged chromosomes, the breakpoints of the inversions were mapped to cixQ sites in supB and ompA, representing inversions of 109 and 210 kb, respectively. In the third case, a 2.1-kb inversion was identified at a cixQ site within the integrated sequences. This derivative itself was a substrate for a second inversion of 1.5 kb between the remaining wild-type cix and still another cixQ site, thus resembling a reversion. In analogy to that which is known from DNA inversion on plasmids, homology of secondary cix sites to wild-type recombination sites is not a strict requirement for inversion to occur on the chromosome. The chromosomal rearrangements which resulted from these Cin-mediated inversions were quite stable and suffered no growth disadvantage compared with the noninverted parental strain. The mechanistic implications and evolutionary relevance of these findings are discussed.Site-specific recombination results in deletions, inversions, or intermolecular fusions depending on the orientations and locations of the recombining sites. In prokaryotic genomes, site-specific DNA inversion is known to play a role in the temporal assembly and expression of some genes that affect the interaction of the organism with its environment, such as tail fiber genes in bacteriophage or pilin, flagellar, or surface antigen genes in bacteria (reviewed in references 23, 32, and 41). Bacteriophage P1 alters its host range by the variable composition of its tail fiber genes that are in part located within the invertible 4.2-kb C segment (16,20). C inversion is a member of the well-characterized Hin family of prokaryotic DNA inversion systems that include H inversion from Salmonella typhimurium (39), G inversion in phage Mu (25, 30), P inversion on the e14 element in Escherichia coli (42), and M inversion on the p15B plasmid of E. coli 15T Ϫ (21). The recombinases in these systems are functionally interchangeable and share 60 to 70% homology at the DNA and amino acid levels (8). The crossover sites for inversion and an enhancer for recombination are also conserved in this family of recombinases.Inversion of the C segment is mediated by the site-specific recombinase Cin, which normally requires two 26-bp inversely repeated crossover sites, cixL and cixR, each consisting of two 12-bp inverted repeats separated by a dinucleotide (AA) at the center of symmetry that determines the polarity of the site and where strand exchange occurs (18). A cis-acting recombinational enhancer, sis(P1),...

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Site-specific recombination in bacteriophage Mu: characterization of binding sites for the DNA invertase Gin.

et al. 1988

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Site‐specific DNA inversion in phage Mu is catalysed by the phage‐encoded DNA invertase Gin and a host factor FIS. We demonstrate that purified Gin protein binds specifically to 34‐bp sequences that flank the G segment as inverted repeats. Each inverted repeat (IR) contains two binding sites for Gin which have to be arranged in a specific configuration to constitute a recombinogenic site. While one of these sites is bound when present alone, the other site is bound only in conjunction with the first one, suggesting cooperative binding. In addition to the sites within the IR, Gin binds with lower affinity to AT‐rich sequences adjacent to the IR. We demonstrate that these sites do not participate in the inversion reaction. The IR itself can be shortened to 25 bp without effect on inversion frequency. Using gel mobility shift experiments on circular permuted fragments containing the IR we show that Gin bends DNA upon binding. We discuss the possibility that DNA bending is related to the formation of a productive synaptic complex.

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Localized conversion at the crossover sequences in the site-specific DNA inversion system of bacteriophage P1

Cited by 41 publications

References 19 publications

Site-specific recombinase genes in three Shigella subgroups and nucleotide sequences of a pinB gene and an invertible B segment from Shigella boydii

Site-specific recombinase genes in three Shigella subgroups and nucleotide sequences of a pinB gene and an invertible B segment from Shigella boydii

Cin-mediated recombination at secondary crossover sites on the Escherichia coli chromosome

Site-specific recombination in bacteriophage Mu: characterization of binding sites for the DNA invertase Gin.

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