Exchange of Type II Dockerin-Containing Subunits of the C. thermocellum Cellulosome as Revealed by SNAP-tags

Journal Article · Tue Jan 01 04:00:00 EST 2013 · FEMS Microbiology Letters

DOI:https://doi.org/10.1111/1574-6968.12029· OSTI ID:1091629

Waller, Benjamin ^[1]; Olson, Daniel G. ^[2]; Currie, Devin ^[1]; Guss, Adam M ^[3]; Lynd, Lee R ^[2]

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1. Dartmouth College
2. Thayer School of Engineering at Dartmouth
3. ORNL

Clostridium thermocellum is a thermophilic anaerobic bacterium which efficiently hydrolyzes and metabolizes cellulose to ethanol through the action of its cellulosome, a multiprotein enzymatic complex. A fluorescent protein probe, consisting of a type II dockerin module fused to a SNAP-tag, was developed in order to gain insight into the quaternary configuration of the cellulosome and to investigate the effect of deleting cipA, the protein scaffold on which the cellulosome is built. Fluorescence microscopy suggested that the probe had localized to polycellulosomal protuberances on the cell surface. Surprisingly, fluorescence intensity did not substantially change in the cipA deletion mutants. Sequential labeling experiments suggested that this was a result of bound type II dockerins from CipA being replaced by unbound type II dockerins from the fluorophore-SNAP-XDocII probe. This mechanism of dockerin exchange could represent an efficient means for modifying cellulosome composition.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1091629
• Journal Information: FEMS Microbiology Letters, Journal Name: FEMS Microbiology Letters Journal Issue: 1 Vol. 338; ISSN 0378-1097
• Country of Publication: United States
• Language: English