Download MendeleyStructure of the Catalytic Domain of the Clostridium Thermocellum Cellulase Celt
Kesavulu, M.M., Tsai, J.-Y., Lee, H.-L., Liang, P.-H., Hsiao, C.-D.(2012) Acta Crystallogr D Biol Crystallogr 68: 310
- PubMed: 22349233
- DOI: https://doi.org/10.1107/S0907444912001990
- Primary Citation of Related Structures:
2YIK - PubMed Abstract:
Cellulases hydrolyze cellulose, a major component of plant cell walls, to oligosaccharides and monosaccharides. Several Clostridium species secrete multi-enzyme complexes (cellulosomes) containing cellulases. C. thermocellum CelT, a family 9 cellulase, lacks the accessory module(s) necessary for activity, unlike most other family 9 cellulases. Therefore, characterization of the CelT structure is essential in order to understand its catalytic mechanism. Here, the crystal structure of free CelTΔdoc, the catalytic domain of CelT, is reported at 2.1 Å resolution. Its structure differs in several aspects from those of other family 9 cellulases. CelTΔdoc contains an additional α-helix, α-helices of increased length and two additional surface-exposed β-strands. It also contains three calcium ions instead of one as found in C. cellulolyticum Cel9M. CelTΔdoc also has two flexible loops at the open end of its active-site cleft. Movement of these loops probably allows the substrate to access the active site. CelT is stable over a wide range of pH and temperature conditions, suggesting that CelT could be used to convert cellulose biomass into biofuel.
Organizational Affiliation:
Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan.
