Functional characterization of the interaction between bacterial adhesin Multivalent Adhesion Molecule 7 (MAM7) protein and its host cell ligands

Anne Marie Krachler, Kim Orth

Research output: Contribution to journalArticle

41 Scopus citations


The ability of a pathogen to rapidly form a stable interaction with the host cell surface is key to its success. Bacterial pathogens use a repertoire of virulence factors, but their efficient use relies on close contact between the host and the pathogen. We have recently identified a constitutively expressed MAM7 (multivalent adhesion molecule 7), which is widely distributed in Gram-negative pathogens and enables them to establish initial contact with the host cell. Here, we describe the dissection of the MAM7 interaction with the host cell surface into two distinct binding events, involving the host protein fibronectin and the membrane phospholipid phosphatidic acid. We analyzed which domains within MAM7 and fibronectin are necessary for complex formation. We further studied phosphatidic acid binding by MAM7 using site-directed mutagenesis and liposome association assays and demonstrated that a specific distribution of basic charge on MAM7 is required for high affinity binding. Finally, we showed that fibronectin and phosphatidic acid binding to MAM7 are not mutually exclusive and that the three molecules likely assemble into a tripartite complex on the host cell surface.

Original languageEnglish (US)
Pages (from-to)38939-38947
Number of pages9
JournalJournal of Biological Chemistry
Issue number45
StatePublished - Nov 11 2011


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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