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Connecting Structure and Function in Anaerobic Fungal Cellulosomes


EMSL Project ID
51373

Abstract

This proposal seeks use of EMSL resources to characterize the unique, multi-enzyme cellulosomes made by anaerobic gut fungi that are found within large herbivores. Cellulosomes enable anaerobic microbes to tether different types of biomass-degrading enzymes together for synergistic breakdown & conversion of lignocellulosic biomass. While cellulosome structure in bacteria is well studied, cellulosome assembly, sub-cellular localization & high-resolution structure in fungi remain unexplored. We have previously isolated four strains representing different fungal genera (Piromyces finnis, Neocallimastix californiae, Caecomyces churrovis, and Anaeromyces robustus), which secrete cellulosomes that are powerful degraders of unpretreated biomass. Previous genomic, transcriptomic, and biochemical analysis of these strains (in collaboration with the JGI & EMSL) have revealed the "parts list" that comprise cellulosomes in fungi, and suggest a unique scaffolding mechanism, localization, and post-translational modifications inherent in these complexes that could govern their functional rearrangement and utility in biotech applications. We seek to partner with EMSL to (1) determine the composition and structure of purified fungal cellulosomes in 4 representative fungal strains via cryo-TEM and native mass spectrometry. Further, we will (2) elucidate the driving forces underlying complex assembly using molecular simulation techniques. Finally, we will (3) characterize by correlative structural-chemical imaging how cellulosome structure allows anaerobic fungi to degrade crude, lignin-rich plant biomass. Outcomes of this project synergize well with ongoing research efforts funded by DOE-BER, and will reveal critical attributes of fungal cellulosomes that can be engineered and exploited for bio-based fuel & chemical production.

Project Details

Project type
Large-Scale EMSL Research
Start Date
2020-10-01
End Date
2022-09-30
Status
Closed

Team

Principal Investigator

Michelle O'Malley
Institution
University of California, Santa Barbara

Co-Investigator(s)

M. Scott Shell
Institution
University of California, Santa Barbara

Team Members

Stephen Lillington
Institution
University of California, Santa Barbara