Disease relevance of O2R_123

• To determine the physiologically important features of site-specific recombination by Escherichia coli Tn3 resolvase we analyzed the salient properties of the reaction in vivo [1].
• The resolvase partially complements the UV and hydroxyurea hypersensitivity and associated aberrant mitoses of an rqh1(-) mutant [2].
• The broad-host-range plasmid pAM beta 1 from Gram-positive bacteria encodes a resolvase, designated Res beta, which shares homology with the proteins of the resolvase-invertase family [3].
• The resolvase/invertase domain of the site-specific recombinase TnpX is functional and recognizes a target sequence that resembles the junction of the circular form of the Clostridium perfringens transposon Tn4451 [4].
• DNA cleavage by the A22R resolvase of vaccinia virus [5].

High impact information on O2R_123

• In vitro recombination by Tn3 resolvase of plasmids containing two directly repeated recombination (res) sites generates two singly interlinked catenated rings [6].
• A putative binding site may be located in the N-terminal portion of the TnpR (resolvase) structural gene sequences [7].
• Examination of the Tn501 DNA sequence also reveals a potential tnpM coding sequence upstream of the Tn501 resolvase gene [7].
• To dissect the pathways of Holliday junction processing in a eukaryote, we have targeted an Escherichia coli Holliday junction resolvase to the nuclei of fission yeast recombination-deficient mutants and analysed their phenotypes [2].
• We conclude that the specificity of recombination is achieved by a three-stage recognition system: binding of resolvase to separate sites, formation of the synaptosome and determination of site orientation from within the complex [8].

Chemical compound and disease context of O2R_123

• Norfloxacin-induced DNA cleavage occurs at the dif resolvase locus in Escherichia coli and is the result of interaction with topoisomerase IV [9].

Biological context of O2R_123

• A two-plasmid system in which one plasmid served as substrate while the other encoded both resolvase and a thermolabile repressor of resolvase transcription provided controlled, synchronous recombination [1].
• Sequence analysis indicated that TnAtcArs is 12 444 bp in length and has 40 bp terminal inverted repeat sequences and divergently transcribed resolvase and transposase genes that are related to the Tn21-transposon subfamily [10].
• Our results demonstrate the functional autonomy of the resolvase catalytic domain and open the way to creating "custom-built" recombinases that act at chosen natural target sequences [11].
• The dif resolvase locus of the Escherichia coli chromosome can be replaced by a 33-bp sequence, but function depends on location [12].
• Induction of the transcriptional fusions results in production of resolvase, which in turn, catalyzes excision of a linked tetracycline-resistance reporter gene flanked by direct repeats of res, the DNA sequences at which resolvase functions [13].

Associations of O2R_123 with chemical compounds

• Expression of resolvase results in excision of tet, restoring a functional cat gene; induced lysogens survive and are chloramphenicol resistant [14].
• The intermediate accumulates at low reaction temperatures and is stabilized by crosslinking of the resolvase protomers with glutaraldehyde [8].
• With one exception, where a glutamate residue had been replaced by leucine, the activity of these mutants was similar to that of wild-type Tn21 resolvase [15].
• We propose a model for Tn4451 excision and insertion in which the resolvase/invertase domain of TnpX introduces 2-bp staggered cuts at these GA dinucleotides [4].

Physical interactions of O2R_123

• The tnpR promoter had 40% of lac promoter efficiency its activity being autoregulated by binding of resolvase to res, as shown by fusion to the galactokinase gene [16].

Analytical, diagnostic and therapeutic context of O2R_123

• We have isolated in quantitative yield the synaptic intermediate formed during site-specific recombination by Tn3 resolvase and characterized it by restriction endonuclease mapping, electron microscopy and topological methods [8].
• We used site-directed mutagenesis to investigate such residues in the RusA resolvase [17].
• We have constructed a genetic bioassay for inhibitors of site-specific recombination by transposon Tn3 resolvase [18].

References