PASTA domain of bacterial serine/threonine kinase pknB-like proteins. PknB is a member of a group of related transmembrane sensor kinases present in many gram positive bacteria, which has been shown to regulate cell shape in Mycobacterium tubercolosis. PknB is a receptor-like transmembrane protein with an extracellular signal sensor domain (containing multiple PASTA domains) and an intracellular, eukaryotic serine/threonine kinase-like domain. The PASTA domain is found at the C-termini of several Penicillin-binding proteins (PBPs) and bacterial serine/threonine kinases. The name PASTA is derived from PBP and Serine/Threonine kinase Associated domain.