Protein Domain : Outer membrane usher protein IPR000015

Type	Family
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 and an outer membrane protein which has been termed a molecular 'usher' [, , ]. The usher protein is rather large (from 86 to 100kDa) 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 high,they 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 [, ].
Short Name	Fimb_usher