title: Collagen IV-derived peptide binds hydrophobic cavity of Legionella pneumophila Mip and interferes with bacterial epithelial transmigration.
abstract: The Legionella virulence factor Mip (macrophage infectivity potentiator) contributes to bacterial dissemination within infected lung tissue. The Mip protein, which belongs to the enzyme family of FK506-binding proteins (FKBP), binds specifically to collagen IV. We identified a surface-exposed Mip-binding sequence in the NC1 domain of human collagen IV α1. The corresponding collagen IV-derived peptide (P290) co-precipitated with Mip and competitively inhibited the Mip-collagen IV binding. Transmigration of Legionella pneumophila across a barrier of NCI-H292 lung epithelial cells and extracellular matrix was efficiently inhibited by P290. This significantly reduced transmigration was comparable to the inefficient transmigration of PPIase-negative Mip mutant or rapamycin-treated L. pneumophila. Based on NMR data and docking studies a model for the mode of interaction of P290 and Mip was developed. The amino acids of the hydrophobic cavity of Mip, D142 and to a lesser extent Y185 were identified to be part of the interaction surface. In the complex structure of Mip(77-213) and P290, both amino acid residues form hydrogen bonds to P290. Utilizing modelling, molecular dynamics (MD) simulations and structural data of human PPIase FKBP12, the most related human orthologue of Mip, we were able to propose optimized P290 variants with increased binding specificity and selectivity for the putative bacterial drug target Mip.
authors.affiliation: Institut für Mikrobiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
authors.forename: Can
authors.initials: C
authors.lastname: Ünal
authors.forename: Kai F
authors.initials: KF
authors.lastname: Schwedhelm
authors.forename: Alexandra
authors.initials: A
authors.lastname: Thiele
authors.forename: Matthias
authors.initials: M
authors.lastname: Weiwad
authors.forename: Kristian
authors.initials: K
authors.lastname: Schweimer
authors.forename: Frederike
authors.initials: F
authors.lastname: Frese
authors.forename: Gunter
authors.initials: G
authors.lastname: Fischer
authors.forename: Jörg
authors.initials: J
authors.lastname: Hacker
authors.forename: Cornelius
authors.initials: C
authors.lastname: Faber
authors.forename: Michael
authors.initials: M
authors.lastname: Steinert
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D002460:Cell Line; D024141:Collagen Type IV / Q000378:metabolism*; D004847:Epithelial Cells / Q000382:microbiology; D054884:Host-Pathogen Interactions; D006801:Humans; D047468:Immunoprecipitation; D016952:Legionella pneumophila / Q000472:pathogenicity*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D019906:Nuclear Magnetic Resonance, Biomolecular; D019696:Peptidylprolyl Isomerase / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D057705:Transendothelial and Transepithelial Migration
chemical_list: D001426:Bacterial Proteins; D024141:Collagen Type IV; C512922:Mip protein, Legionella pneumophila; D019696:Peptidylprolyl Isomerase