Lipoic acid is an organosulphur compound that is an essential coenzyme in several multienzyme complexes, including pyruvate dehydrogenase, 2-oxoglutarate dehydrogenase and the glycine cleavage system. Many Gram-positive bacteria, such as Bacillus subtilis, require three proteins for lipoic acid cofactor biosynthesis: LipJ, LipL and LipM [, ]. LipM is a lipoate:protein ligase that transfers an octanoyl moiety from acyl-carrier protein to the GcvH protein of the glycine cleavage system. LipL, an octanoyltransferase, then transfers this moiety from GcvH to other enzyme complexes. LipA inserts the sulphur group to form the active lipoate cofactor.This entry represents the LipM component of this system.
This family includes export proteins involved in capsule polysaccharide biosynthesis, such as KpsS and LipB . Capsule polysaccharide modification protein lipB/A is involved in the phospholipid modification of the capsular polysaccharide and is a strong requirement for its translocation to the cell surface. The capsule of Neisseria meningitidis serogroup B and of other meningococcal serogroups and other Gram-negative bacterial pathogens, are anchored in the outer membrane through a 1,2-diacylglycerol moiety. The lipA and lipB genes are located on the 3' end of the ctr operon. lipA and lipB do not encode proteins responsible for diacylglycerophosphatidic acid substitution of the meningococcal capsule polymer, but they are required for proper translocation and surface expression of the lipidated polymer [].KpsS is an unusual sulphate-modified form of the capsular polysaccharide in Rhizobium loti (Mesorhizobium loti). Many plants, including R. loti, enter into symbiotic relationships with bacteria that allow survival in nutrient-limiting environments. KpsS functions as a fucosyl sulphotransferase in vitro. The kpsS gene product shares no significant amino acid similarity with previously identified sulphotransferases []. Sulphated cell surface polysaccharides are required for optimum nodule formation but limit growth rate and nodule colonisation in M. loti [].
Lipoic acid is an organosulphur compound that is an essential coenzyme in several multienzyme complexes, including pyruvate dehydrogenase, 2-oxoglutarate dehydrogenase and the glycine cleavage system. Many Gram-positive bacteria, such as Bacillus subtilis, require three proteins for lipoic acid cofactor biosynthesis: LipJ, LipL and LipM [, ]. LipM is a lipoate:protein ligase that transfers an octanoyl moiety from acyl-carrier protein to the GcvH protein of the glycine cleavage system. LipL, an octanoyltransferase, then transfers this moiety from GcvH to other enzyme complexes. LipA inserts the sulphur group to form the active lipoate cofactor.This entry represents the LipL component of this system. It includes Lipoyl-[GcvH]:protein N-lipoyltransferase from Listeria monocytogenes serovar 1/2a () []and Octanoyl-[GcvH]:protein N-octanoyltransferase () from Bacillus subtilis [].
