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| ==New Delhi Metallo-β-Lactamase== | | ==Karyopherin β2== |
| <Structure load='4eyl' size='350' frame='true' align='right' caption='Insert caption here' scene='Insert optional scene name here NDN1' />
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| The New Delhi metallo-β-lactamase (<scene name='37/372730/Asymmetrical_4eyl/2'>NMD-1</scene>) in complex with meropenem (<scene name='37/372730/Symmetrical_4eyl/1'>Chain A</scene>) demonstrates the mechanism in which the active site binds and hydrolyzed the a carbapenem, in this case meropenem.
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| 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.
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| The active site contains key features for hydrolyzing carbapenems:
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| Zinc ion 1(<scene name='37/372730/Chaina_cornflowerblue_zn1/1'>Zn1</scene>) is coordinated by three histidine residues:<scene name='37/372730/Chaina_cornflowerblue_zn1__2/1'>H120, H122 and H189</scene>.
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| Zinc ion 2 (<scene name='37/372730/Symmetrical_4eyl_zn2/3'>Zn2</scene>) is coordinated by three residues: <scene name='37/372730/Symmetrical_4eyl_zn2_/1'>H250, C208, and D124</scene>.
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| 3-D structure of the NDM-1 show two orthogonal views: side view of NDM-1 and looking into the <scene name='37/372730/Chaina_cornflowerblue_zn1_/2'>active site</scene>. 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.
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