Interestingly, even maximum IPTG concentrations are unable to restore the growth rate of the mutant to the SH1000 wild type values. Thus, YsxC could potentially be an interesting target for novel drug development. Galperin and Koonin cite YsxC in the top 10 list of ‘known unknowns’ of highly attractive targets for experimental study of conserved hypothetical proteins in S. aureus [26]. Nevertheless, it is extremely important Panobinostat mw to verify essentiality and analyse gene function in relevant pathogens as not all genes essential in one species maybe so in another.

Tandem affinity purification was originally developed in yeast [27] and has been extensively used in other organisms [28–31], however, not previously in S. aureus. TAP tagging of YsxC and subsequent purification indicated interactions with a number of proteins, the majority of which had functions related to or were integral parts of the ribosome. These were 30 S ribosomal proteins S2 and S10, and 50 S ribosomal protein L17. This indicates that the function of YsxC is likely to be related to the ribosome. However, the ribosome is a complex structure and a large number of processes are required for its correct function, including the construction of subunits from ribosomal proteins

and RNA and the see more assembly of the subunits into the whole ribosome before the translation process. Much of the exact details of these processes and which additional factors are required are unknown. S2 and S10 are not located together on the assembled ribosome but involved in the later stages of 30 S assembly [32]. Thalidomide In contrast, 50 S ribosomal protein L17,

which is localized on the surface of the subunit, binds to 23S rRNA, and even after extensive treatment to dissociate proteins can be found in the core of the 50 S subunit [33–35]. Importantly, B. subtilis L17 over-expression in E. coli results in abnormal cell division and nucleoid segregation becoming ultimately lethal [36]. Similarly, in B. subtilis, a mutation altering L17 was reported to cause temperature sensitivity and a sporulation defect [37]. Interestingly, depletion of YsxC in B. subtilis results in cell elongation, abnormal cell curvature and nucleoid condensation [38]. Similarly, depletion of YihA in E. coli also impairs cell division [16]. Importantly, deficiency of other small molecular weight GTPases in various species, including ObgE in E. coli, and Bex in B. subtilis also appear to affect cytokinesis and chromosome partitioning [39, 40]. Whether these phenotypes are due to the absence of YsxC (and/or L17) or other P-loop GTPases directly impinging on the cell division-related apparatus or a downstream pleiotropic effect remains to be studied. Our light and transmission electron microscopy studies of the cellular morphology of S.