Rad51 facilitates filament assembly of meiosis-specific Dmc1 recombinase.

Dmc1 recombinases are essential to homologous recombination in meiosis. Here, we studied the kinetics of the nucleoprotein filament assembly of Dmc1 using single-molecule tethered particle motion experiments and in vitro biochemical assay. ScDmc1 nucleoprotein filaments are less stable than the ScRad51 ones because of the kinetically much reduced nucleation step.

Phosphorylation at the D53 but Not the T65 Residue of CovR Determines the Repression of and Transcription in 1- and 49-Type Group A Streptococci.

CovR/CovS is a two-component regulatory system in group A and primarily acts as a transcriptional repressor. The D53 residue of CovR (CovR) is phosphorylated by the sensor kinase CovS, and the phosphorylated CovR protein binds to the intergenic region of to inhibit transcription. Nonetheless, the transcription of and is suppressed in mutants.