Crystal structure of the secreted protein HP1454 from the human pathogenHelicobacter pylori

HP1454 is a protein of 303 amino acids found in the extracellular milieu of Helicobacter pylori. The protein structure, crystallized in the orthorhombic C2221 space group with one molecule per asymmetric unit, has been determined using the single-wavelength anomalous dispersion method. HP1454 exhibits an elongated bent shape, composed of three distinct domains. Each domain possesses a fold already present in other structures: Domain I contains a three-strand antiparallel β-barrel flanked by a long α-helix, Domain II is an anti-parallel three-helix bundle, and Domain III a β-sheet flanked by two α-helices. The overall assembly of the protein does not bear any similarity with known structures. © 2014 Wiley Periodicals, Inc.