Open AccessExchange of type II dockerin‐containing subunits of the C lostridium thermocellum cellulosome as revealed by SNAP ‐tags
Author(s) -
Waller Benjamin H.,
Olson Daniel G.,
Currie Devin H.,
Guss Adam M.,
Lynd Lee R.
Publication year - 2013
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12029
Subject(s) - cellulosome , clostridium thermocellum , chemistry , biochemistry , biophysics , cellulase , cellulose , biology
C lostridium 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 cip A , 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 cip A deletion mutants. Sequential labeling experiments suggested that this was a result of bound type II dockerins from C ip A being replaced by unbound type II dockerins from the fluorophore‐ SNAP ‐ XD oc II probe. This mechanism of dockerin exchange could represent an efficient means for modifying cellulosome composition.