Protein Domain : Type IV pilus inner membrane component PilM IPR005883

Type	Family
Description	Bacterial type IV pili are surface filaments critical for diverse biological processes including surface and host cell adhesion, colonisation, biofilm formation, twitching motility, DNA uptake during natural transformation and virulence [ , ]. The proteins necessary to form the type IV pili inner-membrane complex, are included in the pilMNOPQ operon which encodes the cytoplasmic actin-like protein PilM, PilN, PilO, the periplasmic lipoprotein PilP and the outer-membrane secretin PilQ. The inner-membrane PilM/N/O/P complex is required for the optimal function of the outer-membrane secretin PilQ. This cluster is highly conserved across the type IV pilus-producing bacterial species, and all of these proteins have been shown to be essential for twitching motility [, ].The type IV pilus inner membrane component PilM is required for competency and pilus biogenesis [ , ]. PilM associates with PilNO heterodimers by binding the conserved cytoplasmic N terminus of PilN. Binding to PilN induce conformational changes that allow PilM to bind its own N-terminal and form dimers. It also binds ATP, which facilitates PilN interaction [ , ]. This protein is required for the assembly of the type IV fimbria in P. aeruginosa and for a similar pilus-like structure in Synechocystis. It is also found in species such as Deinococcus described as having natural transformation (for which a type IV pilus-like structure is proposed) but not fimbria.This entry also includes Competence protein A from Haemophilus influenzae in which this cluster is annotated as comA/B/C/D/E.
Short Name	PilM