Characterization of the CipA Scaffolding Protein and In Vivo Production of a Minicellulosome in Clostridium acetobutylicum

Recombinant Cellulase and Cellulosome Systems

“…Interestingly, this bacterium is not cellulolytic, however investigation of its genome sequence reveals a cellulosomal gene cluster encoding a number of hydrolytic enzymes as well as a scaffold protein CipA [64,108]. Sabathe and colleagues were successful in engineering C. acetobutylicum to secrete and assemble a functional minicellulosome in vivo [109]. Since CipA had been previously demonstrated to not be secreted in this organism, the authors replaced the original signal peptide with that of the C. cellulolyticum scaffold protein CipC.…”

“…Since CipA had been previously demonstrated to not be secreted in this organism, the authors replaced the original signal peptide with that of the C. cellulolyticum scaffold protein CipC. Overexpression and secretion of a truncated version of CipA containing two cohesin domains and a CBD resulted in its binding with endogenous cellulase Cel48A, and formation of a secreted cellulosome in vivo [109]. In analyzing the activity of the recombinant cellulosome on Avicel, bacterial cellulose, PASC and carboxymethyl cellulose, no detectable activity was observed when using the crystalline substrates, as is the case for native C. acetobutylicum.…”

The Past, Present, and Future of Biofuels – Biobutanol as Promising Alternative

“…This is curious because the genome of C. acetobutylicum contains a number of genes, which code for cellulosome components (Nölling et al, 2001). By their overexpression in E. coli or C. acetobutylicum it could be shown that part of the respective proteins are functional (LopezContreras et al, 2003;Sabathé & Soucaille, 2003). Phosphotransferase systems perform the uptake of many sugars.…”

Biological research survey for the efficient conversion of biomass to biofuels.

“…Re-engineering of these complexes holds the potential to further improve the efficiency of cell wall deconstruction and cellulose breakdown (16)(17)(18)(19)(20). Detailed structural and biophysical characterization of these complexes as they interact with lipid membranes will be needed for modeling and subsequent optimization of designer cellulosome complexes.…”

“…Detailed structural and biophysical characterization of these complexes as they interact with lipid membranes will be needed for modeling and subsequent optimization of designer cellulosome complexes. In particular, understanding the cohesin-dockerin interaction is critical to producing designer-cellulosomes (15)(16)(17)(18)(19)(20)(21)(22). Critical issues are binding affinities and reversibility, the origin of inter and intraspecies selectivity, and conformational changes of the enzymes upon docking or as a function of Ca 2+ concentration that affect their activity.…”