1js4: Difference between revisions
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==Overview== | ==Overview== | ||
Cellulase E4 from Thermomonospora fusca is unusual in that it has, characteristics of both exo- and endo-cellulases. Here we report the, crystal structure of a 68K M(r) fragment of E4 (E4-68) at 1.9 A, resolution. E4-68 contains both a family 9 catalytic domain, exhibiting an, (alpha/alpha)6 barrel fold, and a family III cellulose binding domain, having an antiparallel beta-sandwich fold. While neither of these folds is, novel, E4-68 provides the first cellulase structure having interacting, catalytic and cellulose binding domains. The complexes of E4-68 with, cellopentaose, cellotriose and cellobiose reveal conformational changes, associated with ligand binding and allow us to propose a catalytic, mechanism for family 9 enzymes. We also provide evidence that E4 has two, novel | Cellulase E4 from Thermomonospora fusca is unusual in that it has, characteristics of both exo- and endo-cellulases. Here we report the, crystal structure of a 68K M(r) fragment of E4 (E4-68) at 1.9 A, resolution. E4-68 contains both a family 9 catalytic domain, exhibiting an, (alpha/alpha)6 barrel fold, and a family III cellulose binding domain, having an antiparallel beta-sandwich fold. While neither of these folds is, novel, E4-68 provides the first cellulase structure having interacting, catalytic and cellulose binding domains. The complexes of E4-68 with, cellopentaose, cellotriose and cellobiose reveal conformational changes, associated with ligand binding and allow us to propose a catalytic, mechanism for family 9 enzymes. We also provide evidence that E4 has two, novel characteristics: first it combines exo- and endo-activities and, second, when it functions as an exo-cellulase, it cleaves off, cellotetraose units. | ||
==About this Structure== | ==About this Structure== | ||
1JS4 is a | 1JS4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermobifida_fusca Thermobifida fusca] with GLC and CA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cellulase Cellulase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.4 3.2.1.4] Structure known Active Sites: AA1, AB1, CA1, CA2, CA3 and CA4. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1JS4 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: glycosyl hydrolase]] | [[Category: glycosyl hydrolase]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 15:10:12 2007'' | ||
