Protein kinase that is responsible for triggering spore germination in response to muropeptides, signaling bacteria to exit dormancy. PrkC is thus a germination receptor that binds peptidoglycan fragments containing m-Dpm (meso-diaminopimelate), which act as spore germinants. Autophosphorylates and phosphorylates EF-G (elongation factor G, fusA); the latter modification is likely necessary for germination in response to peptidoglycan (PubMed:12399479). Another group did not detect phosphorylation of EF-G (PubMed:19246764). PrkC is a substrate in vitro of the cotranscribed phosphatase PrpC, which suggests that they form a functional couple in vivo. Might also be involved in sporulation and biofilm formation. Does not seem to be involved in stress response. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Bryostatin activates PrkC activity and induces germination, whereas staurosporine inhibits PrkC and significantly reduced peptidoglycan-dependent germination. Kinase activity of isolated N-terminus stimulated by poly-L-lysine or myelin basic protein (PubMed:19246764). Homodimer. Is associated with the inner membrane of the spore. The cytoplasmic domain has Ser/Thr kinase activity (PubMed:12406230). The C-terminal extracellular domain containing the PASTA repeats binds peptidoglycan. Autophosphorylation on threonine residue(s) and serine residue considerably increases the kinase activity of the protein. Dephosphorylated in vitro by PrpC. Spores lacking this gene fail to germinate in the presence of peptidoglycan fragments or purified GlcNAc-MurNAc tripeptides and tetrapeptides. They still respond to the nutrient germinant L-alanine and to the chemical germinant Ca(2+)-dipicolinic acid, indicating that the spores are still capable of germinating and that PrkC is not involved in nutrient or chemical germination. PubMed:18984160 shows that peptidoglycan fragments serve as a novel mechanism of interspecies bacterial signaling that likely indicates the presence of growing bacteria and thus serve as a signal for dormant cells that growth-promoting conditions exist. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.