1rh9
Family GH5 endo-beta-mannanase from Lycopersicon esculentum (tomato)
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OverviewOverview
The three-dimensional crystal structure of tomato (Lycopersicon esculentum) beta-mannanase 4a (LeMAN4a) has been determined to 1.5 A resolution. The enzyme adopts the (beta/alpha)(8) fold common to the members of glycohydrolase family GH5. The structure is comparable with those of the homologous Trichoderma reesei and Thermomonospora fusca beta-mannanases: There is a conserved three-stranded beta-sheet located near the N terminus that stacks against the central beta-barrel at the end opposite the active site. Three noncanonical beta-helices surround the active site. Similar helices are found in T. reesei but not T. fusca beta-mannanase. By analogy with other beta-mannanases, the catalytic acid/base residue is E204 and the nucleophile residue is E318. The active site cleft of L. esculentum beta-mannanase most closely resembles that of the T. reesei isozyme. A model of substrate binding in LeMAN4a is proposed in which the mannosyl residue occupying the -1 subsite of the enzyme adopts the (1)S(5) skew-boat conformation.
About this StructureAbout this Structure
1RH9 is a Single protein structure of sequence from Solanum lycopersicum. Active as Mannan endo-1,4-beta-mannosidase, with EC number 3.2.1.78 Full crystallographic information is available from OCA.
ReferenceReference
Three-dimensional structure of (1,4)-beta-D-mannan mannanohydrolase from tomato fruit., Bourgault R, Oakley AJ, Bewley JD, Wilce MC, Protein Sci. 2005 May;14(5):1233-41. PMID:15840830
Page seeded by OCA on Thu Feb 21 14:50:53 2008