5ELM

Crystal structure of L-aspartate/glutamate specific racemase in complex with L-glutamate

Summary for 5ELM

• Entry DOI: 10.2210/pdb5elm/pdb
• Related: 5ELL
• Descriptor: Asp/Glu_racemase family protein, GLYCEROL, GLUTAMIC ACID, ... (5 entities in total)
• Functional Keywords: asp/glu racemase, l-form specific racemase, amino acid enantiomers, isomerase
• Biological source: Escherichia coli
• Total number of polymer chains: 4
• Total formula weight: 106243.83

Authors

Ahn, J.W.,Chang, J.H.,Kim, K.J. (deposition date: 2015-11-04, release date: 2015-11-18, Last modification date: 2023-11-08)

Primary citation

Ahn, J.W.,Chang, J.H.,Kim, K.J.
Structural basis for an atypical active site of an l-aspartate/glutamate-specific racemase from Escherichia coli
Febs Lett., 589:3842-3847, 2015

PubMed Abstract: We determined the crystal structure of EcL-DER to elucidate protein function and substrate specificity. Unlike other asp/glu racemases, EcL-DER has an unbalanced pair of catalytic residues, Thr83/Cys197, at the active site that is crucial for L- to D-unidirectional racemase activity. EcL-DER exhibited racemase activity for both L-glutamate and L-aspartate, but had threefold higher activity for L-glutamate. Based on the structure of the EcL-DER(C197S) mutant in complex with L-glutamate, we determined the binding mode of the L-glutamate substrate in EcL-DER and provide a structural basis for how the protein utilizes L-glutamate as a main substrate. The unidirectionality, despite an equilibrium constant of unity, can be understood in terms of the Haldane relationship.

PubMed: 26555188
DOI: 10.1016/j.febslet.2015.11.003

Experimental method

X-RAY DIFFRACTION (2 Å)