MCB 4207 Lecture Notes - Lecture 15: Sortase, Pilin, Bacterial Adhesin
Document Summary
Receptor (host) binds to a ligand/adhesion (bacteria) specific. Specificity of adherence: tropism at tissue level: bind certain tissues over others. Same niche, different specificities: host species specificities: which host you cause infection in, genetic specificity within a species: make you prone or susceptible to a certain pathogen. Know experimentally how to look for evidence of receptor/adhesin interactions (slide. Adhesion: adhesins, pili, afimbrial adhesins, bind to extracellular matrix. Two functions of pili: attachment, solid media motility. Type 4: bundle-forming pilus: modified amino acid at n-terminus distinct from other types. Curli: synthesis process called nucleation-dependent polymerization, built from the distal end down, opposite from the rest. Gram-positive pilus assembly: pilin subunits with lpxtg motif targeted to cm by general sec-dep secretion, sortase cleaves between t/g. Transient thiol-ester bond between sortase and threonine: oligomerization attack of thiol ester by lys of pilin subunit, peptidoglycan linkae thiol ester attacked by nh2 of pd pentapeptide. Type iv pilus can be gram-positive or gram-negative.
