New Insights From Computer Simulations May Improve Biomass Deconstruction

Researchers performed molecular dynamics simulations and free energy calculations on both the wild type (WT) and D39N mutant of the C. thermocellum Type I cohesin-dockerin complex.

The Science

Scientists at the DOE BioEnergy Science Center (BESC) have made a significant step in understanding the recalcitrance of biomass to microbial deconstruction. Microbes that break down plant biomass have large extracellular enzyme complexes, known as cellulosomes, that break down plant cell walls. The organization and assembly of the cellulosome, an extracellular multienzyme complex produced by anaerobic bacteria, is mediated by the high-affinity interaction of cohesin domains from scaffolding proteins with dockerins of cellulosomal enzymes. The BESC team used computational simulations to understand the binding dynamics of two cellulosome proteins that play critical roles in the assembly of the cellulosome. The simulations included a typical cellulosome complex and one with mutant proteins that cause a major change in protein-protein recognition sites needed for normal assembly of the cellulosome. This information will help BESC researchers redesign cellulosomal modules that can degrade biomass more efficiently than normal cellulosomes.

Funding

This research made possible with computational time on the ORNL Kraken Cray XT5 Supercomputer.