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.
1zen
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /> <applet load="1zen" size="450" color="white" frame="true" align="right" spinBox="true" caption="1zen, resolution 2.5Å" /> '''CLASS II FRUCTOSE-1,...)
Next diff →
Revision as of 07:00, 18 November 2007
|
CLASS II FRUCTOSE-1,6-BISPHOSPHATE ALDOLASE
Overview
BACLGROUND: Aldolases catalyze a variety of condensation and cleavage, reactions, with exquisite control on the stereochemistry. These enzymes, therefore, are attractive catalysts for synthetic chemistry. There are two, classes of aldolase: class I aldolases utilize Schiff base formation with, an active-site lysine whilst class II enzymes require a divalent metal, ion, in particular zinc. Fructose-1,6-bisphosphate aldolase (FBP-aldolase), is used in gluconeogenesis and glycolysis; the enzyme controls the, condensation of dihydroxyacetone phosphate with glyceraldehyde-3-phosphate, to yield fructose-1,6-bisphosphate. Structures are available for class I, FBP-aldolases but there is a paucity of detail on the class II enzymes., Characterization is sought to enable a dissection of structure/activity, relationships which may assist the construction of designed aldolases for, use as biocatalysts in synthetic chemistry. RESULTS: The structure of the, dimeric class II FBP-aldolase from Escherichia coli has been determined, using data to 2.5 A resolution. The asymmetric unit is one subunit which, presents a familiar fold, the (alpha/beta)8 barrel. The active centre, at, the C-terminal end of the barrel, contains a novel bimetallic-binding site, with two metal ions 6.2 A apart. One ion, the identity of which is not, certain, is buried and may play a structural or activating role. The other, metal ion is zinc and is positioned at the surface of the barrel to, participate in catalysis. CONCLUSIONS: Comparison of the structure with a, class II fuculose aldolase suggests that these enzymes may share a common, mechanism. Nevertheless, the class II enzymes should be subdivided into, two categories on consideration of subunit size and fold, quaternary, structure and metal-ion binding sites.
About this Structure
1ZEN is a Single protein structure of sequence from Escherichia coli with ZN as ligand. The following page contains interesting information on the relation of 1ZEN with [The Glycolytic Enzymes]. Active as Fructose-bisphosphate aldolase, with EC number 4.1.2.13 Full crystallographic information is available from OCA.
Reference
The crystal structure of a class II fructose-1,6-bisphosphate aldolase shows a novel binuclear metal-binding active site embedded in a familiar fold., Cooper SJ, Leonard GA, McSweeney SM, Thompson AW, Naismith JH, Qamar S, Plater A, Berry A, Hunter WN, Structure. 1996 Nov 15;4(11):1303-15. PMID:8939754
Page seeded by OCA on Sun Nov 18 09:07:42 2007
