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 . 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.