3MF7

Crystal Structure of (R)-oxirane-2-carboxylate inhibited cis-CaaD

Summary for 3MF7

• Entry DOI: 10.2210/pdb3mf7/pdb
• Related: 3MF8
• Descriptor: Cis-3-chloroacrylic acid dehalogenase (2 entities in total)
• Functional Keywords: beta-alpha-beta motif, tautomerase, dehalogenase, cis-3-chloroacrylic acid dehalogenase, isomerase, hydrolase
• Biological source: coryneform bacterium
• Total number of polymer chains: 1
• Total formula weight: 16732.59

Authors

Guo, Y.,Serrano, H.,Ernst, S.R.,Johnson Jr., W.H.,Hackert, M.L.,Whitman, C.P. (deposition date: 2010-04-01, release date: 2011-01-12, Last modification date: 2023-09-06)

Primary citation

Guo, Y.,Serrano, H.,Johnson, W.H.,Ernst, S.,Hackert, M.L.,Whitman, C.P.
Crystal structures of native and inactivated cis-3-chloroacrylic acid dehalogenase: Implications for the catalytic and inactivation mechanisms.
Bioorg.Chem., 39:1-9, 2011

PubMed Abstract: The isomeric mixture of cis- and trans-1,3-dichloropropene constitutes the active component of a widely used nematocide known as Telone II®. The mixture is processed by various soil bacteria to acetaldehyde through the 1,3-dichloropropene catabolic pathway. The pathway relies on an isomer-specific hydrolytic dehalogenation reaction catalyzed by cis- or trans-3-chloroacrylic acid dehalogenase, known respectively as cis-CaaD and CaaD. Previous sequence analysis and crystallographic studies of the native and covalently modified enzymes identified Pro-1, His-28, Arg-70, Arg-73, Tyr-103, and Glu-114 as key binding and catalytic residues in cis-CaaD. Mutagenesis of these residues confirmed their importance to the dehalogenation reaction. Crystal structures of the native enzyme (2.01Å resolution) and the enzyme covalently modified at the Pro-1 nitrogen by 2-hydroxypropanoate (1.65Å resolution) are reported here. Both structures are at a resolution higher than previously reported (2.75Å and 2.1Å resolution, respectively). The conformation of the covalent adduct is strikingly different from that previously reported due to its interaction with a 7-residue loop (Thr-32 to Leu-38). The participation of another active site residue, Arg-117, in catalysis and inactivation was also examined. The implications of the combined findings for the mechanisms of catalysis and inactivation are discussed.

PubMed: 21074239
DOI: 10.1016/j.bioorg.2010.10.001

Experimental method

X-RAY DIFFRACTION (1.65 Å)