This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1rh9
From Proteopedia
|
Family GH5 endo-beta-mannanase from Lycopersicon esculentum (tomato)
Overview
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 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.
Reference
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
