East-Asian Helicobacter pylori strains synthesize heptan-deficient lipopolysaccharide
Fig 7
LPS biosynthesis model in H. pylori.
The comparative genomic analysis of the LPS glycosyltransferase genes among H. pylori strains of different ethnic origin, provided genetic evidence for the structural conservation of the Glc-Trio-Core moiety of LPS, and the potential to express Lewis antigens in all H. pylori strains (Fig 4, S3 Table). However, the intermediate region (shaded) varies considerably between LPS from different H. pylori strains. (A): in Western strains (represented by G27) that harbour the heptan transferase gene HP1283 and the GlcNAc transferase gene HP1578, the Lewis antigen synthesis is initiated by the GlcNAc transferase HP1578 onto the intermediate heptan (synthesized by HP1283); (B): in hspEAsia strains represented by the Japanese strains CA2 with its genome sequenced in this study showing the absence of HP1283/HP1578 but the presence of two copies of HP1105 and one copy of JHP0562 (S3 Table column DS), and the established CA2 LPS structures lacking the intermediate heptan as reported in a previous study [19], the Lewis antigen is proposed to be directly attached onto the conserved Glc-Trio-Core structure via a GlcNAc or a Gal residue transferred by the additional HP1105 or JHP0562, respectively.