In: Biology
Can you please explain the molecular components involved in the pathway of SsrA-tagged protein degradation in Vivo? Including the adaptor protein SspB and delivery to ClpX and subsequent degradation by ClpP.
In prokaryotics a conserved small RNA molecule called tmRNA roscues ribosomes from proteins that are abnormally truneated due to the presence of rare confons or degraded mRNA.degradtion of ssrA tagged protien is a central feature of protein quality control in all bacteria during the rescue process,a peptide tag (ssrA) encoded by tmRNA is contranslationally added to the trancted polypeptides therebyt targeting these proteins for protelytic degradation In Eschericha coli ,ClpXP and ClpAP proteins primarily degraded SsrA tagged protiens.thr ATP dependent ClpXP and ClpAP proteins are thought to participate in this process,buy their relative contribution to degradation of ssrA tagged protien in vivo have been unceratun because two adapt protiens,clPs and SspB can modulate proteolysis of thsee substractions.SspB is adimeric adapata protein that increase the rate at which scrA tagged substrate are degraded by trthertet them to the clpXP protease.each sspB submit consists of a folded domain that forms the diner interface and a flexafle c-terminal tail.both wild - type and mustat tags showed highly dynamic SspB interactions . together these results strongly support delivery models in which SspB and slpX bind concurrently to the ssrA tag but also suggest that clashes between sspB and ClpX weaken simultaneous binding during substrate delivery ,this signal making is overcome by tethering SspB to clpX which ensure local concentration high enough to drive tag engagement.this obstract then stimulate mechanism may have envolved to allow additional levels if regulations and could be a common trait of adaptor mediatee protein degradation.