6tn6

Publication Abstract from PubMed

The endo-beta-1,4-mannanase from the hyperthermostable bacterium Thermotoga petrophila (TpMan) is an enzyme that catalyzes the hydrolysis of mannan and heteromannan polysaccharides. Of the three domains that comprise TpMan, the N-terminal GH5 catalytic domain and the C-terminal carbohydrate-binding domain are connected through a central ancillary domain of unknown structure and function. In this study, we report the partial crystal structure of the TpMan at 1.45 A resolution, so far, the first modular hyperthermostable endo-beta-1,4-mannanase structure determined. The structure exhibits two domains, a (beta/alpha)8-barrel GH5 catalytic domain connected via a linker to the central domain with an immunoglobulin-like beta-sandwich fold formed of seven beta-strands. Functional analysis showed that whereas the immunoglobulin-like domain does not have the carbohydrate-binding function, it stacks on the GH5 catalytic domain acting as a thermostabilizing domain and allowing operation at hyperthermophilic conditions. The carbohydrate-binding domain is absent in the crystal structure most likely due to its high flexibility around the immunoglobulin-like domain which may act also as a pivot. These results represent new structural and functional information useful on biotechnological applications for biofuel and food industries.

High-resolution structure of a modular hyperthermostable endo-beta-1,4-mannanase from Thermotoga petrophila: The ancillary immunoglobulin-like module is a thermostabilizing domain.,da Silva VM, Cabral AD, Speranca MA, Squina FM, Muniz JRC, Martin L, Nicolet Y, Garcia W Biochim Biophys Acta Proteins Proteom. 2020 Apr 21;1868(8):140437. doi:, 10.1016/j.bbapap.2020.140437. PMID:32325255^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.