Structural basis of Lewis ^b antigen binding by the Helicobacter pylori adhesin BabA

Abstract

X-ray structure of BabA bound to Lewisb reveals molecular interactions used by H. pylori to colonize the gastric mucosa.

In VitroandIn VivoAntibacterial Activities of Patchouli Alcohol, a Naturally Occurring Tricyclic Sesquiterpene, against Helicobacter pylori Infection

“…S5 in the supplemental material). Adhesive proteins BabA and AlpAB are key factors in H. pylori adhesion that specifically bind to the cell surface proteins Lewis b and laminin, respectively (23,24). Results showed that PA significantly suppressed the adherence of H. pylori to GES-1 cells and inhibited alpA and alpB gene expression.…”

The Prevalence of Helicobacter pylori Virulence Related Genes (hpa and babA2) in Iranian Patients with Gastrointestinal Disorders

“…There are 3 bab alleles (babA1, babA2, and babB) of H. pylori, but only the babA2 gene indicates Lewis-b binding function (6). The BabA adhesion of H. pylori is an external membrane protein that is attached to the fucosylated histoblood group antigens on the outer surface of gastric epithelial receptors (6,7). Duodenal users and adenocarcinoma H. pylori agglutinin (hpa) is a binding protein of H. pylori that is coded by the hpa gene and binds H. pylori to gastric mucosal cells.…”

Helicobacter pylori Strains from Duodenal Ulcer Patients Exhibit Mixed babA/B Genotypes with Low Levels of BabA Adhesin and Lewis b Binding

“…Such recombination events can create ON/OFF switches, e.g., the babA1/babA2 variants, which result in gene silence (babA1) or expression (babA2) [16]. BabB is a non-Le b binding member of the BabA/B/C-family of proteins, with high similarities in the N-and C-terminal domains (and the corresponding gene segments), but extensive differences in the central region of the protein, and in particular in the Le b carbohydrate binding domain (CBD), which is only found in BabA protein [10,14,15].…”

“…BabA belongs to a family that also includes the BabB and BabC proteins [13], that are very similar, but lack the Le b binding adhesin properties. The recent crystal structure of BabA revealed a distinct carbohydrate binding domain, which is missing in the closely related BabB protein [14,15]. The tight BabA-mediated binding and mucosal adherence result in chronic inflammation, with high levels of recruited inflammatory cells [14].…”

“…BabB which is encoded by babB, has similar N-and C-terminal sequences to BabA, but divergent central domains [6,13] and has no Le b binding activity. It is, therefore, thought that the central non-homologous domain of BabA is critical for receptor binding [14,15]. These babA and babB genes can be present in either of the chromosomal loci, that are referred to as locus A (downstream of hypD) and locus B (downstream of s18) [19].…”