Protein Domain : Fimbrial membrane usher, conserved site IPR018030

Type	Conserved_site
Description	In Gram-negative bacteria the biogenesis of fimbriae (or pili) requires a two- component assembly and transport system which is composed of a periplasmicchaperone (see ) and an outer membrane protein which has been termed a molecular 'usher' [, , ]. The usher protein is rather large (from 86 to 100 Kd) and seems to be mainly composed of membrane-spanning β-sheets, astructure reminiscent of porins. Although the degree of sequence similarity of these proteins is not very highthey share a number of characteristics. One of these is the presence of two pairs of cysteines, the first one located in the N-terminal part and the secondat the C-terminal extremity that are probably involved in disulphide bonds. The best conserved region is located in the central part of these proteins.This entry represents the conserved site of the Fimbrial biogenesis outer membrane usher protein.
Short Name	Fimbrial_membr_usher_CS