5y2d
Crystal structure of H. pylori HtrACrystal structure of H. pylori HtrA
Structural highlights
Publication Abstract from PubMedKnowledge of the molecular mechanisms of specific bacterial virulence factors can significantly contribute to antibacterial drug discovery. Helicobacter pylori is a Gram-negative microaerophilic bacterium that infects almost half of the world's population, leading to gastric disorders and even gastric cancer. H. pylori expresses a series of virulence factors in the host, among which high-temperature requirement A (HpHtrA) is a newly identified serine protease secreted by H. pylori. HpHtrA cleaves the extracellular domain of the epithelial cell surface adhesion protein E-cadherin and disrupts gastric epithelial cell junctions, allowing H. pylori to access the intercellular space. Here we report the first crystal structure of HpHtrA at 3.0 A resolution. The structure revealed a new type of HtrA protease trimer stabilized by unique N-terminal domain swapping distinct from other known HtrA homologs. We further observed that truncation of the N terminus completely abrogates HpHtrA trimer formation as well as protease activity. In the presence of unfolded substrate, HpHtrA assembled into cage-like 12-mers or 24-mers. Combining crystallographic, biochemical, and mutagenic data, we propose a mechanistic model of how HpHtrA recognizes and cleaves the well-folded E-cadherin substrate. Our study provides a fundamental basis for the development of anti-H. pylori agents by using a previously uncharacterized HtrA protease as a target. The unique trimeric assembly of the virulence factor HtrA from Helicobacter pylori occurs via N-terminal domain swapping.,Zhang Z, Huang Q, Tao X, Song G, Zheng P, Li H, Sun H, Xia W J Biol Chem. 2019 May 17;294(20):7990-8000. doi: 10.1074/jbc.RA119.007387. Epub, 2019 Apr 1. PMID:30936204[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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