2EEX

Crystal structure of Cel44A, GH family 44 endoglucanase from Clostridium thermocellum

Summary for 2EEX

• Entry DOI: 10.2210/pdb2eex/pdb
• Related: 2E0P 2E4T
• Related PRD ID: PRD_900016
• Descriptor: Endoglucanase, beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose, ZINC ION, ... (7 entities in total)
• Functional Keywords: tim barrel, the composite domain of gh family 5, 30, 39, 51, gh family 44, glycoside hydrolase, hydrolase
• Biological source: Clostridium thermocellum
• Total number of polymer chains: 1
• Total formula weight: 58841.38

Authors

Kitago, Y.,Karita, S.,Watanabe, N.,Sakka, K.,Tanaka, I. (deposition date: 2007-02-19, release date: 2007-09-18, Last modification date: 2023-10-25)

Primary citation

Kitago, Y.,Karita, S.,Watanabe, N.,Kamiya, M.,Aizawa, T.,Sakka, K.,Tanaka, I.
Crystal structure of Cel44A, a glycoside hydrolase family 44 endoglucanase from Clostridium thermocellum.
J.Biol.Chem., 282:35703-35711, 2007

PubMed Abstract: The crystal structure of Cel44A, which is one of the enzymatic components of the cellulosome of Clostridium thermocellum, was solved at a resolution of 0.96 A. This enzyme belongs to glycoside hydrolase family (GH family) 44. The structure reveals that Cel44A consists of a TIM-like barrel domain and a beta-sandwich domain. The wild-type and the E186Q mutant structures complexed with substrates suggest that two glutamic acid residues, Glu(186) and Glu(359), are the active residues of the enzyme. Biochemical experiments were performed to confirm this idea. The structural features indicate that GH family 44 belongs to clan GH-A and that the reaction catalyzed by Cel44A is retaining type hydrolysis. The stereochemical course of hydrolysis was confirmed by a (1)H NMR experiment using the reduced cellooligosaccharide as a substrate.

PubMed: 17905739
DOI: 10.1074/jbc.M706835200

Experimental method

X-RAY DIFFRACTION (2 Å)