4DBF

Crystal structures of Cg1458

Summary for 4DBF

• Entry DOI: 10.2210/pdb4dbf/pdb
• Related: 4DBH
• Descriptor: 2-HYDROXYHEPTA-2,4-DIENE-1,7-DIOATE ISOMERASE, MAGNESIUM ION (3 entities in total)
• Functional Keywords: oxaloacetate decarboxylase, isomerase
• Biological source: Corynebacterium glutamicum
• Total number of polymer chains: 2
• Total formula weight: 62473.90

Authors

Ran, T.T.,Xu, D.Q.,Wang, W.W.,Gao, Y.Y.,Wang, M.T. (deposition date: 2012-01-15, release date: 2012-11-28, Last modification date: 2023-11-08)

Primary citation

Ran, T.,Gao, Y.,Marsh, M.,Zhu, W.,Wang, M.,Mao, X.,Xu, L.,Xu, D.,Wang, W.
Crystal structures of Cg1458 reveal a catalytic lid domain and a common catalytic mechanism for FAH family.
Biochem.J., 449:51-60, 2013

PubMed Abstract: Cg1458 was recently characterized as a novel soluble oxaloacetate decarboxylase. However, sequence alignment identified that Cg1458 has no similarity with other oxaloacetate decarboxylases and instead belongs to the FAH (fumarylacetoacetate hydrolase) family. Differences in the function of Cg1458 and other FAH proteins may suggest a different catalytic mechanism. To help elucidate the catalytic mechanism of Cg1458, crystal structures of Cg1458 in both the open and closed conformations have been determined for the first time up to a resolution of 1.9 Å (1 Å=0.1 nm) and 2.0 Å respectively. Comparison of both structures and detailed biochemical studies confirmed the presence of a catalytic lid domain which is missing in the native enzyme structure. In this lid domain, a glutamic acid-histidine dyad was found to be critical in mediating enzymatic catalysis. On the basis of structural modelling and comparison, as well as large-scale sequence alignment studies, we further determined that the catalytic mechanism of Cg1458 is actually through a glutamic acid-histidine-water triad, and this catalytic triad is common among FAH family proteins that catalyse the cleavage of the C-C bond of the substrate. Two sequence motifs, HxxE and Hxx…xxE have been identified as the basis for this mechanism.

PubMed: 23046410
DOI: 10.1042/BJ20120913

Experimental method

X-RAY DIFFRACTION (1.9 Å)