Type V Pilus is Assembled by a Protease-mediated Strand-exchange Mechanism

Abstract

Adhesion is an essential ability for bacteria to survive and occupy a niche in the environment. Filamentous adhesive machinery called “pilus” or “fimbria” plays an important role in colonization, biofilm formation, and infection of many bacteria. Newly characterized type V pilus is common in the class Bacteroidia bacteria including a major oral pathogen Porphyromonas gingivalis. The monomer form and polymerized form of type V pilus subunits were revealed by X-ray crystallography and cryo-EM analysis, which led to the proposal of a unique model of type V pilus assembly mechanism involving protease-mediated strand exchange. These insights broaden our knowledge of infection mechanisms and microbiota development of class Bacteroidia bacteria.