3IK2

Crystal Structure of a Glycoside Hydrolase Family 44 Endoglucanase produced by Clostridium acetobutylium ATCC 824

Summary for 3IK2

• Entry DOI: 10.2210/pdb3ik2/pdb
• Descriptor: Endoglucanase A, CHLORIDE ION, CALCIUM ION, ... (7 entities in total)
• Functional Keywords: tim-like barrel, hydrolase
• Biological source: Clostridium acetobutylicum
• Total number of polymer chains: 1
• Total formula weight: 58890.57

Authors

Warner, C.D.,Hoy, J.A.,Ford, C.F.,Honzatko, R.B.,Reilly, P.J. (deposition date: 2009-08-05, release date: 2009-08-18, Last modification date: 2023-09-06)

Primary citation

Warner, C.D.,Hoy, J.A.,Shilling, T.C.,Linnen, M.J.,Ginder, N.D.,Ford, C.F.,Honzatko, R.B.,Reilly, P.J.
Tertiary structure and characterization of a glycoside hydrolase family 44 endoglucanase from Clostridium acetobutylicum.
Appl.Environ.Microbiol., 76:338-346, 2010

PubMed Abstract: A gene encoding a glycoside hydrolase family 44 (GH44) protein from Clostridium acetobutylicum ATCC 824 was synthesized and transformed into Escherichia coli. The previously uncharacterized protein was expressed with a C-terminal His tag and purified by nickel-nitrilotriacetic acid affinity chromatography. Crystallization and X-ray diffraction to a 2.2-A resolution revealed a triose phosphate isomerase (TIM) barrel-like structure with additional Greek key and beta-sandwich folds, similar to other GH44 crystal structures. The enzyme hydrolyzes cellotetraose and larger cellooligosaccharides, yielding an unbalanced product distribution, including some glucose. It attacks carboxymethylcellulose and xylan at approximately the same rates. Its activity on carboxymethylcellulose is much higher than that of the isolated C. acetobutylicum cellulosome. It also extensively converts lichenan to oligosaccharides of intermediate size and attacks Avicel to a limited extent. The enzyme has an optimal temperature in a 10-min assay of 55 degrees C and an optimal pH of 5.0.

PubMed: 19915043
DOI: 10.1128/AEM.02026-09

Experimental method

X-RAY DIFFRACTION (2.2 Å)