2017年3月19日 · This new Xer complex is based on a single tyrosine recombinase called XerS (356 aa) that acts on an atypical 31 bp recombination site called difSL in the presence of dimers.

1997年8月29日 · Xer site-specific recombination functions in maintaining circular replicons in the monomeric state in Escherichia coli. Two recombinases of the bacteriophage λ integrase family, XerC and XerD, are required for recombination at the chromosomal site, dif, and at a range of plasmid-borne sites.

1999年10月15日 · We demonstrate that Xer recombination at plasmid dif sites occurs efficiently only when FtsK is present and under conditions that allow chromosomal dimer formation, whereas recombination at the plasmid sites cer and psi is independent of these factors.

克隆鲍曼不动杆菌xerC和xerD基因，并使用重组克隆来补充同源大肠杆菌突变体。 互补菌株支持质粒二聚体的解析，并且与大肠杆菌和肺炎克雷伯菌质粒的情况一样，当细胞在低渗透压生长培养基中生长时，活性增强。 结合实验表明，部分纯化的鲍曼不动杆菌XerC和XerD蛋白（XerC Ab和XerD Ab ）结合合成的Xer位点特异性重组位点，其中一些具有从现有鲍曼不动杆菌质粒推导的核苷酸序列。 与自杀底物一起孵育导致 DNA 与重组酶（可能是 XerC Ab）共价连接，表明重组 …

2017年3月20日 · In Escherichia coli and most bacteria, dimers are resolved to monomers by site-specific recombination, a process performed by two Chromosomally Encoded tyrosine Recombinases (XerC and XerD). XerCD recombinases act at a 28 bp recombination site dif, which is located at the replication terminus region of the chromosome.

2000年6月2日 · In Xer site-specific recombination, two related recombinases, XerC and XerD, belonging to the tyrosine recombinase family of site-specific recombinases, convert dimers of the Escherichia coli chromosome and multicopy plasmids to monomers, thereby ensuring their effective segregation at cell division (Recchia et al., 1999).

In XerD, the arrangement of active site residues supports a cis cleavage mechanism. Biochemical evidence for DNA bending is encompassed in a model that accommodates extensive biochemical and genetic data, and in which the DNA is wrapped around an alpha-helix in a manner similar to that observed for CAP complexed with DNA.

1999年10月10日 · We propose that the chromosome dimer- and FtsK-dependent process that activates Xer recombination at plasmid dif also activates Xer recombination at chromosomal dif. The defects in chromosome segregation that result from mutation of the FtsK C-terminus are attributable to the failure of Xer recombination to resolve chromosome dimers to monomers.

2001年9月7日 · We show that XerC or XerD variants lacking their N-terminal domains are active in recombination when combined with their wild-type partner. Nevertheless, the normal pattern of catalysis is dramatically altered; strand exchange by the recombinase variant is stimulated, while that by the wild-type partner recombinase is impaired.

2019年9月9日 · Xer-cise is a technique using antibiotic resistance cassettes flanked by dif sites allowing spontaneous and accurate excision from bacterial chromosomes with a high frequency through the action of the cellular recombinase XerCD. Here, we report a significant improvement of Xer-cise in Mycobacteria.