reca protein การใช้

• This tail can be bound by RecA protein, which promotes strand exchange with an intact homologous DNA duplex.
• In this bacterium, the RecA protein interacts with the incoming single-stranded DNA ( ssDNA ) to form striking filamentous structures.
• Very unusual recombination or parallel triplexes, or R-DNA, have been assumed to form under RecA protein in the course of homologous recombination.
• In doing so, the RecR subunit helps to both detach the SSBP molecules from RecO and load molecules of the RecA protein onto the 3'overhang.
• Stohl and Seifert showed that the bacterial RecA protein, that mediates recombinational repair of DNA damage, plays an important role in " gonococcal " survival.
• The RecA protein can be loaded onto the SSBP-coated 3'overhang in one of two distinct pathways, one that requires the RecFOR enzyme or one that requires the RecOR enzyme.
• When RecBCD resumes unwinding, it now cleaves the opposite strand ( " i . e . ", the 5'tail ) and loads RecA protein onto the 3-ended strand.
• The RecA protein is then actively loaded onto the 3'tail by RecBCD . At some undetermined point RecBCD dissociates from the DNA, although RecBCD can unwind at least 60 kb of DNA without falling off.
• Recognition of the Chi site also changes the RecBCD enzyme so that it cuts the DNA strand with Chi and begins loading multiple RecA proteins onto the single-stranded DNA with the newly generated 3'end.
• Although the proteins and specific mechanisms involved in their initial phases differ, the two pathways are similar in that they both require single-stranded DNA with a 3'end and the RecA protein for strand invasion.
• The protection afforded by RecA protein may be linked to transformation, the process by which recipient " gonococci " take up DNA from neighboring " gonococci " and integrate this DNA into the recipient genome through recombination.
• As a postdoctoral fellow with Dr . I . R . Lehman at Stanford University School of Medicine, Dr . Weinstock and Kevin McEntee discovered that the RecA protein of " E . coli " catalyzed strand transfer in genetic recombination.
• As part of the transformation process, the RecA protein interacts with entering single-stranded DNA ( ssDNA ) to form RecA / ssDNA nucleofilaments that scan the resident chromosome for regions of homology and bring the entering ssDNA to the corresponding region, where strand exchange and homologous recombination occur.
• In either case the resulting 3 single-stranded DNA ( ssDNA ) is bound by multiple molecules of RecA protein that facilitate " strand invasion, " in which one strand of a homologous double-stranded DNA is displaced by the RecA-associated ssDNA . Strand invasion forms a joint DNA molecule called a D-loop.
• Various end-points are possible indicators of the triggering of the SOS system; activation of the RecA protein, cleavage of the LexA repressor, expression of any of the SOS genes, etc . One of the simplest assays consists of monitoring the expression of an SOS gene by means of fusion with lacZ, the structural gene for " E . coli " ?-galactosidase.