Identification of a 3-deoxy-D-manno-octulosonic acid biosynthetic operon in Moraxella catarrhalis and analysis of a KdsA-deficient isogenic mutant.

ABSTRACT: Lipooligosaccharide (LOS), a predominant surface-exposed component of the outer membrane, has been implicated as a virulence factor in the pathogenesis of Moraxella catarrhalis infections. However, the critical steps involved in the biosynthesis and assembly of M. catarrhalis LOS currently remain undefined. In this study, we used random transposon mutagenesis to identify a 3-deoxy-D-manno-octulosonic acid (KDO) biosynthetic operon in M. catarrhalis with the gene order pyrG-kdsA-eno. The lipid A-KDO molecule serves as the acceptor onto which a variety of glycosyl transferases sequentially add the core and branch oligosaccharide extensions for the LOS molecule. KdsA, the KDO-8-phosphate synthase, catalyzes the first step of KDO biosynthesis and is an essential enzyme in gram-negative enteric

SUBMITTER: Luke NR 

PROVIDER: S-EPMC219605 | biostudies-literature | 2003 Nov

REPOSITORIES: biostudies-literature