Proline Isomerization: From the Chemistry and Biology to Therapeutic Opportunities.

Proline isomerization, the process of interconversion between the - and -forms of proline, is an important and unique post-translational modification that can affect protein folding and conformations, and ultimately regulate protein functions and biological pathways. Although impactful, the importance and prevalence of proline isomerization as a regulation mechanism in biological systems have not been fully understood or recognized. Aiming to fill gaps and bring new awareness, we attempt to provide a wholistic review on proline isomerization that firstly covers what proline isomerization is and the basic chemistry behind it.

Distribution of RecBCD and AddAB recombination-associated genes among bacteria in 33 phyla.

Homologous recombination plays key roles in fundamental processes such as recovery from DNA damage and in bacterial horizontal gene transfer, yet there are still open questions about the distribution of recognized components of recombination machinery among bacteria and archaea. RecBCD helicase-nuclease plays a central role in recombination among Gammaproteobacteria like ; while bacteria in other phyla, like the Firmicute , use the related AddAB complex. The activity of at least some of these complexes is controlled by short DNA sequences called crossover hotspot instigator (Chi) sites.