Protein Domain : Type II secretion system protein GspG, C-terminal IPR013545

Type	Domain
Description	This entry represents the C-terminal domain of GspG. GspG is the major pseudopilin of the type 2 secretion systems (T2SSs). The N-terminal hydrophobic helices of the GspG subunits arrange within the core of the pseudopilus, with the C-terminal domains and the Ca2+-binding sites located at the surface. The structure of GspG (also known as PulG) has been revealed [ ]. The type II secretion system (T2SS) is one of several extracellular secretion systems in gram-negative bacteria. It delivers toxins and a range of hydrolytic enzymes including proteases, lipases and carbohydrate-active enzymes to the cell surface or extracellular space [ ]. T2SS systems are composed of 11 to 15 different proteins, which are generally called GspA to GspO and GspS. The T2SS spans the two bacterial membranes and ensures secretion of folded proteins across the outer membrane pore formed by GspD. The inner membrane complex contains GspC, GspL, GspM, and GspF. The cytoplasmic domains of GspL and GspF interact with an ATPase, GspE. GspE is thought to energize the formation of a short pseudopilus by several pilin-like proteins, GspG to GspK []. GspD has been shown to interact with the inner membrane component GspC []. The T2SS pseudopilus is a periplasmic filament composed of the major pseudopilin, EpsG, and four minor pseudopilins, EpsH, EpsI, EpsJ and EpsK. Pseudopilus is assembled by the polymerization of GspG (also known as PulG) subunits. Pseudopilin proteins have a conserved N-terminal hydrophobic segment followed by a more variable C-terminal periplasmic and globular domain [ ].
Short Name	T2SS_protein-GspG_C