YjbH is a family of Gram-negative ß-barrel outer-membrane lipoproteins that act as putative porins. YbjH is one of four gene-products expressed from an operon, yjbEFGH, which is regulated by the Rcs phosphorelay in a RcsA-dependent manner, similar to that of other exopolysaccharide biosynthetic pathways. It is highly possible that the yjbEFGH operon encodes a system involved in EPS secretion since none of the products is predicted to have enzymic activity, the products are all secreted and YbjH and F are predicted to be ß-barrel lipoproteins similar to porins. It may be that the operon products play some role in biofilm formation and/or matrix production