The X-ray crystal structure of the extracellular adhesion domain of SabA from Helicobacter pylori — ASN Events
  1. Schedule
  2. Session 5: Poster Session A
  3. The X-ray crystal structure of the extracellular adhesion domain of SabA from Helicobacter pylori

The X-ray crystal structure of the extracellular adhesion domain of SabA from Helicobacter pylori (#113)

Stanley Nguyen 1 , Siew Siew Pang 1 , Andrew Perry 1 , Joe Tiralongo 2 , Christopher Day 2 , Terry Kwok-Schuelein 1 , James Whisstock 1
  1. Monash University, Clayton, VIC, Australia
  2. School of Biomolecular and Physical Science, Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia

The Helicobacter pylori outer membrane protein (Hop) family is a large superfamily consisting at least 33 paralogous genes. The most important role of Hop family is involved in adherence to the mucus layer of the gastric epithelium. The binding of Hop family causes persistent infections in the pathogenesis of H. pylori gastritis and associated diseases.

There are two well-known members of Hop family are BabA and SabA, which mediate adherence to specific Lewis carbohydrate antigens. To the date, no representative structure of Hop family has been determined and the mechanisms of these specific interactions are poorly understood.

Here, we report X-ray crystal structures of extracellular adhesion domain of SabA. The adhesion domain SabA structure reveals a predominantly α-helical molecule in the L-shape. We also identified the binding pocket, formed between two helical strands at the top of the structure. By using surface plasmon resonance experiment, the mutations in binding site located alongside one of helical strand greatly reduced the Lewis-carbohydrate binding activity.

Taken together, Extracellular adhesion domain of SabA structure represents the first reported structure in whole Hop protein family and provides further understanding of the mechanism of interaction between Hop proteins with their carbohydrate counterparts.