3MMW

Crystal structure of endoglucanase Cel5A from the hyperthermophilic Thermotoga maritima

Summary for 3MMW

• Entry DOI: 10.2210/pdb3mmw/pdb
• Related: 3MMU
• Descriptor: Endoglucanase, CADMIUM ION (3 entities in total)
• Functional Keywords: tim barrel fold, hydrolase
• Biological source: Thermotoga maritima
• Total number of polymer chains: 4
• Total formula weight: 150990.61

Authors

Pereira, J.H.,Chen, Z.,McAndrew, R.P.,Sapra, R.,Chhabra, S.R.,Sale, K.L. (deposition date: 2010-04-20, release date: 2010-07-28, Last modification date: 2023-09-06)

Primary citation

Pereira, J.H.,Chen, Z.,McAndrew, R.P.,Sapra, R.,Chhabra, S.R.,Sale, K.L.,Simmons, B.A.,Adams, P.D.
Biochemical characterization and crystal structure of endoglucanase Cel5A from the hyperthermophilic Thermotoga maritima.
J.Struct.Biol., 172:372-379, 2010

PubMed Abstract: Tm_Cel5A, which belongs to family 5 of the glycoside hydrolases, is an extremely stable enzyme among the endo-acting glycosidases present in the hyperthermophilic organism Thermotoga maritima. Members of GH5 family shows a common (β/α)(8) TIM-barrel fold in which the catalytic acid/base and nucleophile are located on strands β-4 and β-7 of the barrel fold. Thermally resistant cellulases are desirable for lignocellulosic biofuels production and the Tm_Cel5A is an excellent candidate for use in the degradation of polysaccharides present on biomass. This paper describes two Tm_Cel5A structures (crystal forms I and II) solved at 2.20 and 1.85Å resolution, respectively. Our analyses of the Tm_Cel5A structure and comparison to a mesophilic GH5 provides a basis for the thermostability associated with Tm_Cel5A. Furthermore, both crystal forms of Tm_Cel5A possess a cadmium (Cd(2+)) ion bound between the two catalytic residues. Activity assays of Tm_Cel5A confirmed a strong inhibition effect in the presence of Cd(2+) metal ions demonstrating competition with the natural substrate for the active site. Based on the structural information we have obtained for Tm_Cel5A, protein bioengineering can be used to potentially increase the thermostability of mesophilic cellulase enzymes.

PubMed: 20599513
DOI: 10.1016/j.jsb.2010.06.018

Experimental method

X-RAY DIFFRACTION (1.85 Å)