The RecA protein of Deinococcus radiodurans (RecA(Dr)) is essential for the extreme radiation resistance of this organism. The RecA(Dr) protein has been cloned and expressed in Escherichia coli and purified from this host. In some respects, the RecA(Dr) protein and the E. coli RecA (RecA(Ec)) proteins are close functional homologues. RecA(Dr) forms filaments on single-stranded DNA (ssDNA) that ...

The RecX protein is a potent inhibitor of RecA protein activities. RecX functions by specifically blocking the extension of RecA filaments. In vitro, this leads to a net disassembly of RecA protein from circular single-stranded DNA. Based on multiple observations, we propose that RecX has a RecA filament capping activity. This activity has predictable effects on the formation and disassembly of...

صلاخلا ــ ة : مت ةقرولا هذه يف ءاشنإ يف هدعاسملل مدقتم ماظن بناوج ذيفنتو ميمصت ضرع قتو و مي ءادأ حيحصت تارفش لأا ءاطخ ةليلق لا ةناتم ، ةينبم ىلع ءوفاكتلا رايتخا . موقي امه نيتيسيئر نيتفيظوب ةساردلا هذه يف مدقتملا ماظنلا : 1 ادأ باسحل ةيزاوتملا هاآاحملا ء تارفش حيحصت لأا ءاطخ ةليلق نمزب ةفاثكلا ادج ريصق ةنراقم ةمظنأب ةاآاحملا ةدوجوملا . 2 ةليلق ءاطخلأا حيحصت تارفشو فعضلا قطانم صحف نع ة...

Mycobacterium tuberculosis complex (MTBC) members are causative agents of human and animal tuberculosis. Differentiation of MTBC members is required for appropriate treatment of individual patients and for epidemiological purposes. Strains from six MTBC species -- M. tuberculosis, M. bovis subsp. bovis, M. bovis BCG, M. africanum, M. pinnipedii, and "M. canetti" -- were studied using gyrB-restr...

gyrB fragments (about 1.2 kb) of 9 Vibrio alginolyticus strains were sequenced, and their phylogenetic relationship with other closely related Vibrio species was analyzed. All the V. alginolyticus strains grouped into one strongly supported cluster in the phylogenetic tree. There were 54 base variations among the 1167 bp mutual gyrB regions of 11 V. alginolyticus strains; all the V. alginolytic...

Nucleotide sequences of small-subunit rRNA (16S rRNA) are most commonly used for the identication and characterization of bacteria and their complex communities. However, 16S rRNA evolves slowly and is often not very convenient to resolve bacterial strains at the species level. We have therefore attempted to develop a rapid and more convenient system for bacterial identi cation using the gyrB g...

We show that certain DNA sequences have the ability to influence the positioning of RecA monomers in RecA-DNA complexes. A tendency for RecA monomers to be phased was observed in RecA protein complexes with several oligonucleotides containing a recombinational hotspot sequence, the chi-site from Escherichia coli. This influence was observed in both the 5' to 3' and 3' to 5' directions with resp...

Interspecific complementation of an Escherichia coli recA mutant with plasmids containing a gene bank of Rhizobium meliloti DNA was used to identify a clone which contains the recA gene of R. meliloti. The R. meliloti recA protein can function in recombination and in response to DNA damage when expressed in an E. coli recA host, and hybridization studies have shown that DNA sequence homology ex...

OBJECTIVES Decreased susceptibility to fluoroquinolones has become a major problem for the successful therapy of human infections caused by Salmonella enterica, especially the life-threatening typhoid and paratyphoid fevers. METHODS By using Luminex xTAG beads, we developed a rapid, reliable and cost-effective multiplexed genotyping assay for simultaneously detecting 11 mutations in gyrA, gyr...