Uridyl peptide antibiotics

Pacidamycins, napsamycins, mureidomycins, and sansanmycins are uridyl peptide antibiotics isolated from Streptomyces sp. strains and show potent inhibitory activity against phosphoMurVAc-pentapeptide translocase (MraY), an essential enzyme in bacterial cell wall peptidoglycan biosynthesis [269, 270]. 

The structure of the uridyl peptide antibiotics was elucidated through extensive NMR studies. These studies assigned the cis geometry of the exocyclic enamide double bond based on an NOE (nuclear Overhauser effect) signal between the vinylic proton and the methylene protons of the amino sugar [271, 272], Boojamra et al. established the absolute stereochemistry of 2,3-diaminobutyric acid as (25,35) [273], while Bugg and coworkers demonstrated the remarkable stability of the enamide present in the uridyl peptide antibiotics [274], 

The common structural skeleton of the uridyl peptide antibiotics, the (25,35)-diaminobutyric acid (DABA) residue, serves as a connection point for the 3 -deoxyuridine moiety via a 4, 5 -enamide linkage. The DABA residue is acylated on both nitrogen substituents by peptide chains. 

The pacidamycin gene cluster was identified and sequenced, thereby providing the first example of a biosynthetic cluster for a member of the uridyl peptide family of antibiotics. Zhang et al. reported that the 31-kb gene cluster consisted of 22 

Pacidamycin 1 Pacidamycin 2 Pacidamycin 3 Pacidamycin 4 Pacidamycin 5 Pacidamycin 5T Pacidamycin 6 Pacidamycin 7 Pacidamycin D 

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