3DXV: The Crystal Structure Of Alpha-Amino-Epsilon-Caprolactam Racemase From Achromobacter Obae

Alpha-amino-epsilon-caprolactam (ACL) racemase (ACLR) from Achromobacter obae catalyzes the interconversion of l- and d-ACL. ACLR belongs to the fold-type I group of pyridoxal 5'-phosphate (PLP) dependent enzymes. In this study, the first crystal structures of a fold-type I racemase are solved for the native form and epsilon-caprolactam-complexed form of ACLR at 2.21 and 2.40 A resolution, respectively. Based on the location of epsilon-caprolactam in the complex structure, the substrate-binding site is assigned between Trp49 and Tyr137. The carboxyl group of Asp210 is a reasonable candidate that recognizes the nitrogen atom of a lactam or amide in the substrate. Based on a structural comparison with fold-type III alanine racemase, Tyr137 is potentially the acid/base catalytic residue that is essential for the two-base racemization mechanism. The overall structure of ACLR is similar to that of fold-type I enzymes. A structural comparison with these enzymes explains the different reaction specificities.
PDB ID: 3DXVDownload
MMDB ID: 85266
PDB Deposition Date: 2008/7/25
Updated in MMDB: 2012/12
Experimental Method:
x-ray diffraction
Resolution: 2.21  Å
Source Organism:
Similar Structures:
Biological Unit for 3DXV: dimeric; determined by author and by software (PISA)
Molecular Components in 3DXV
Label Count Molecule
Proteins (2 molecules)
Alpha-amino-epsilon-caprolactam Racemase
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB