According to the Ambler structural classification of beta-lactamases, the New Delhi metallo-beta-lactamase (NDM) enzyme belongs to which class?
- A Class A serine beta-lactamases
- B Class C cephalosporinases
- C Class B metallo-beta-lactamases ✓
- D Class D oxacillinases
Correct answer: C. Class B metallo-beta-lactamases
Explanation
The Ambler scheme divides beta-lactamases by active site into four molecular classes. Class C enzymes are metallo-beta-lactamases that require zinc at the active site and are inhibited by chelating agents such as EDTA. NDM, IMP and VIM all fall here. Classes A, B and D use an active-site serine residue; KPC is class A, AmpC is class B, and OXA-type enzymes are class D.
Reference: Ananthanarayan and Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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