Sandbox 130
New Delhi Metallo-β-LactamaseNew Delhi Metallo-β-Lactamase
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The New Delhi metallo-β-lactamase () in complex with meropenem () demonstrates the mechanism in which the active site binds and hydrolyzed the a carbapenem, in this case meropenem. Zn1 (coordinated by three histidine residues), acts as a major constituent of oxyanion hole to stabilize tetrahedral intermediate. It also acts as a Lewis acid for interaction with lactam carbonyl in Michaelis complex and acts to suppress the pKa of the hyrdolytic water to (~5-6) to facilitate it's nucleophilic role. The active site contains key features for hydrolyzing carbapenems:
Zinc ion 1() is coordinated by three histidine residues:. Zinc ion 2 () is coordinated by three residues: .
3-D structure of the NDM-1 show two orthogonal views: side view of NDM-1 and looking into the active site. Zn1 and Zn2 are shown in cyan. The residues that coordinate with Zn1 are colored in orange and the residues that coordinate with Zn2 are colored in yellow.