title: Cloning, purification and preliminary crystallographic analysis of the Helicobacter pylori leucyl aminopeptidase-bestatin complex.
abstract: Helicobacter pylori is an important human pathogenic bacterium associated with numerous severe gastroduodenal diseases, including ulcers and gastric cancer. Cytosolic leucyl aminopeptidase (LAP) is an important housekeeping protein that is involved in peptide and protein turnover, catabolism of proteins and modulation of gene expression. LAP is upregulated in metronidazole-resistant H. pylori, which suggests that, in addition to having an important housekeeping role, LAP contributes to the mechanism of drug resistance. Crystals of H. pylori LAP have been grown by the hanging-drop vapour-diffusion method using polyethylene glycol as a precipitating agent. The crystals belonged to the primitive triclinic space group P1, with unit-cell parameters a = 97.5, b = 100.2, c = 100.4 Å, α = 75.4, β = 60.9, γ = 81.8°. An X-ray diffraction data set was collected to 2.8 Å resolution from a single crystal. Molecular-replacement results using these data indicate that H. pylori LAP is a hexamer with 32 symmetry.
authors.affiliation: Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Joyanta K
authors.initials: JK
authors.lastname: Modak
authors.forename: Anna
authors.initials: A
authors.lastname: Roujeinikova
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D016480:Helicobacter pylori / Q000737:chemistry* / Q000201:enzymology / Q000235:genetics; D007930:Leucine / Q000031:analogs & derivatives* / Q000737:chemistry; D007931:Leucyl Aminopeptidase / Q000737:chemistry* / Q000235:genetics; D011485:Protein Binding; D055503:Protein Multimerization; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D007931:Leucyl Aminopeptidase; D007930:Leucine; C012211:ubenimex
keywords: Helicobacter pylori; bestatin; leucyl aminopeptidase