Enzymes of thermophilic anaerobic bacteria hydrolyzing cellulose, xylan, and other beta-glucans

Genes for 24 glycosylhydrolases of three thermophilic anaerobic eubacteria (Clostridium thermocellum, Anaerocellum thermophilum, and Thermotoga neapol itana) were cloned in Escherichia coli. The nucleotide sequences were deter mined for 13 genes, and the domain structures of the encoded proteins were deduced by analysis of predicted amino acid sequences. Multidomain organiza tion was found for the cellobiohydrolase CbhA of C. thermocellum, xylanase XynA, cellulases CelD and CelA of A. thermophilum, laminarinase LamA and xy lanase XynA of T. neapolitana. The genes for T. neapolitana enzymes hydroly zing laminarin (lamA and bglB) and cellulose (celA and celB), as well as th e A. thermophilum enzymes hydrolyzing cellulose and various glucans (celA a nd manA), were found to be clustered in the host chromosome.