Fosfomycin is a bactericidal antibiotic used for uncomplicated urinary tract infections. Its mechanism of action involves inhibition of which specific enzyme in the bacterial cell wall synthesis pathway?

• A D-alanyl-D-alanine synthetase
• B Alanine racemase
• C Transpeptidase (PBP)
• D UDP-N-acetylmuramic acid enolpyruvyl transferase (MurA) ✓

Explanation

Fosfomycin inhibits MurA (enolpyruvyl transferase), which catalyzes the first committed step in peptidoglycan synthesis by adding enolpyruvate to UDP-N-acetylglucosamine. This early inhibition prevents the formation of N-acetylmuramic acid, a vital building block for the bacterial cell wall. Transpeptidase is inhibited by beta-lactams. B-alanyl-B-alanine synthetase and alanine racemase are inhibited by cycloserine.

Reference: Katzung and Trevor's Pharmacology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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