Resolving dual binding conformations of cellulosome cohesin-dockerin complexes using single-molecule force spectroscopy.

ABSTRACT: Receptor-ligand pairs are ordinarily thought to interact through a lock and key mechanism, where a unique molecular conformation is formed upon binding. Contrary to this paradigm, cellulosomal cohesin-dockerin (Coh-Doc) pairs are believed to interact through redundant dual binding modes consisting of two distinct conformations. Here, we combined site-directed mutagenesis and single-molecule force spectroscopy (SMFS) to study the unbinding of Coh:Doc complexes under force. We designed Doc mutations to knock out each binding mode, and compared their single-molecule unfolding patterns as they were dissociated from Coh using an atomic force microscope (AFM) cantilever. Although average bulk measurements were unable to resolve the differences in Doc binding modes due to the similarity of the in

SUBMITTER: Jobst MA 

PROVIDER: S-EPMC4728124 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature