1H0B

Endoglucanase cel12A from Rhodothermus marinus

Summary for 1H0B

• Entry DOI: 10.2210/pdb1h0b/pdb
• Descriptor: CELLULASE, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID (3 entities in total)
• Functional Keywords: cellulase, endoglucanase, hydrolase
• Biological source: RHODOTHERMUS MARINUS
• Total number of polymer chains: 2
• Total formula weight: 57483.55

Authors

Crennell, S.J.,Hreggvidsson, G.O.,Nordberg-Karlsson, E. (deposition date: 2002-06-17, release date: 2003-06-12, Last modification date: 2023-12-13)

Primary citation

Crennell, S.J.,Hreggvidsson, G.O.,Nordberg Karlsson, E.
The Structure of Rhodothermus Marinus Cel12A, a Highly Thermostable Family 12 Endoglucanase, at 1.8 A Resolution
J.Mol.Biol., 320:883-, 2002

PubMed Abstract: Cellulose is one of the most abundant polysaccharides in nature and microorganisms have developed a comprehensive system for enzymatic breakdown of this ubiquitous carbon source, a subject of much interest in the biotechnology industry. Rhodothermus marinus produces a hyperthermostable cellulase, with a temperature optimum of more than 90 degrees C, the structure of which is presented here to 1.8 A resolution. The enzyme has been classified into glycoside hydrolase family 12; this is the first structure of a thermophilic member of this family to have been solved. The beta-jelly roll fold observed has identical topology to those of the two mesophilic members of the family whose structures have been elucidated previously. A Hepes buffer molecule bound in the active site may have triggered a conformational change to an active configuration as the two catalytic residues Glu124 and Glu207, together with dependent residues, are observed in a conformation similar to that seen in the structure of Streptomyces lividans CelB2 complexed with an inhibitor. The structural similarity between this cellulase and the mesophilic enzymes serves to highlight features that may be responsible for its thermostability, chiefly an increase in ion pair number and the considerable stabilisation of a mobile region seen in S. lividans CelB2. Additional aromatic residues in the active site region may also contribute to the difference in thermophilicity.

PubMed: 12095262
DOI: 10.1016/S0022-2836(02)00446-1

Experimental method

X-RAY DIFFRACTION (1.8 Å)