Dr. Constantin Schöler
Biophysics and Molecular Materials
Ludwig-Maximilians-Universität
Munchen, Germany

Thursday, March 6, 2014
3:00 pm (CT)
3269 Beckman Institute

Abstract

Mechanical strength of protein-protein interactions has evolved to resist selection pressure in specific environments. Within the rumen, for example, nanoscale protein networks known as cellulosomes are used by anaerobic bacteria and fungi to digest lignocellulosic substrates. Within these highly sophisticated molecular machines, catalytic subdomains are assembled onto scaffold proteins allowing them to act synergistically. This assembly is mediated via high affinity cohesin dockerin interactions. We used AFM single molecule force spectroscopy and steered molecular dynamics simulations to characterize a cohesin dockerin interaction from R. flavefaciens involved in anchoring the bacterial host cell to cellulosic substrates. In this study we could show for the first time, that an X-module adjacent to the dockerin domain acts a mechanical shield maintaining the integrity of cellulosomes.