3tf4
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Cellulase E4 from Thermomonospora fusca is unusual in that it has | + | 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== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Thermobifida fusca]] | [[Category: Thermobifida fusca]] | ||
| - | [[Category: Karplus, P | + | [[Category: Karplus, P A.]] |
[[Category: Sakon, J.]] | [[Category: Sakon, J.]] | ||
| - | [[Category: Wilson, D | + | [[Category: Wilson, D B.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: GLC]] | [[Category: GLC]] | ||
[[Category: glycosyl hydrolase]] | [[Category: glycosyl hydrolase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:11:31 2008'' |
Revision as of 17:11, 21 February 2008
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ENDO/EXOCELLULASE:CELLOTRIOSE FROM THERMOMONOSPORA
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 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
3TF4 is a Single protein structure of sequence from Thermobifida fusca with and as ligands. Active as Cellulase, with EC number 3.2.1.4 Known structural/functional Sites: , , , , and . Full crystallographic information is available from OCA.
Reference
Structure and mechanism of endo/exocellulase E4 from Thermomonospora fusca., Sakon J, Irwin D, Wilson DB, Karplus PA, Nat Struct Biol. 1997 Oct;4(10):810-8. PMID:9334746
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