Structure of the deacetylase LpxC bound to the antibiotic CHIR-090: Time-dependent inhibition and specificity in ligand binding.

Published

Journal Article

The UDP-3-O-(R-3-hydroxyacyl)-N-acetylglucosamine deacetylase LpxC is an essential enzyme of lipid A biosynthesis in Gram-negative bacteria and a promising antibiotic target. CHIR-090, the most potent LpxC inhibitor discovered to date, displays two-step time-dependent inhibition and kills a wide range of Gram-negative pathogens as effectively as ciprofloxacin or tobramycin. In this study, we report the solution structure of the LpxC-CHIR-090 complex. CHIR-090 exploits conserved features of LpxC that are critical for catalysis, including the hydrophobic passage and essential active-site residues. CHIR-090 is adjacent to, but does not occupy, the UDP-binding pocket of LpxC, suggesting that a fragment-based approach may facilitate further optimization of LpxC inhibitors. Additionally, we identified key residues in the Insert II hydrophobic passage that modulate time-dependent inhibition and CHIR-090 resistance. CHIR-090 shares a similar, although previously unrecognized, chemical scaffold with other small-molecule antibiotics such as L-161,240 targeting LpxC, and provides a template for understanding the binding mode of these inhibitors. Consistent with this model, we provide evidence that L-161,240 also occupies the hydrophobic passage.

Full Text

Duke Authors

Cited Authors

  • Barb, AW; Jiang, L; Raetz, CRH; Zhou, P

Published Date

  • November 20, 2007

Published In

Volume / Issue

  • 104 / 47

Start / End Page

  • 18433 - 18438

PubMed ID

  • 18025458

Pubmed Central ID

  • 18025458

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

Digital Object Identifier (DOI)

  • 10.1073/pnas.0709412104

Language

  • eng

Conference Location

  • United States