TCB Publications - Abstract

Constantin Schoeler, Klara H. Malinowska, Rafael C. Bernardi, Lukas F. Milles, Markus A. Jobst, Ellis Durner, Wolfgang Ott, Daniel B. Fried, Edward A. Bayer, Klaus Schulten, Hermann E. Gaub, and Michael A. Nash. Ultrastable cellulosome-adhesion complex tightens under load. Nature Communications, 5:5635, 2014. (PMC: PMC4266597)

SCHO2014 In contrast to the free enzymes secreted by a majority of cellulolytic microorganisms, certain bacteria and fungi produce large multi-enzyme networks called cellulosomes to convert plant cell walls into fermentable sugars. While network assembly is enabled by protein interactions with commonplace affinities, we show here that certain cellulosomal receptor–ligand interactions exhibit extreme resistance to applied force. Through single molecule force spectroscopy (SMFS) and steered molecular dynamics (SMD) simulations, we characterized the ligand–receptor complex responsible for substrate anchoring in the Ruminococcus flavefaciens cellulosome. We found the complex withstands forces of 600- 750 pN at loading rates of 10-100 nN/s, representing the strongest bimolecular interaction reported thus far, equivalent to half the mechanical strength of a covalent bond. The binding mechanisms discovered including force-activation and inter-domain stabilization suggest mechanical stability as an additional design parameter in the development of biocatalysts for the production of fuels and chemicals from cellulosic biomass.

Download Full Text

The manuscripts available on our site are provided for your personal use only and may not be retransmitted or redistributed without written permissions from the paper's publisher and author. You may not upload any of this site's material to any public server, on-line service, network, or bulletin board without prior written permission from the publisher and author. You may not make copies for any commercial purpose. Reproduction or storage of materials retrieved from this web site is subject to the U.S. Copyright Act of 1976, Title 17 U.S.C.

Download full text: PDF ( 1.0MB), Supplemental Material ( 2.1MB), Journal