title: Molecular validation of LpxC as an antibacterial drug target in Pseudomonas aeruginosa.
abstract: LpxC [UDP-3-O-(R-3-hydroxymyristoyl)-GlcNAc deacetylase] is a metalloamidase that catalyzes the first committed step in the biosynthesis of the lipid A component of lipopolysaccharide. A previous study (H. R. Onishi, B. A. Pelak, L. S. Gerckens, L. L. Silver, F. M. Kahan, M. H. Chen, A. A. Patchett, S. M. Galloway, S. A. Hyland, M. S. Anderson, and C. R. H. Raetz, Science 274:980-982, 1996) identified a series of synthetic LpxC-inhibitory molecules that were bactericidal for Escherichia coli. These molecules did not inhibit the growth of Pseudomonas aeruginosa and were therefore not developed further as antibacterial drugs. The inactivity of the LpxC inhibitors for P. aeruginosa raised the possibility that LpxC activity might not be essential for all gram-negative bacteria. By placing the lpxC gene of P. aeruginosa under tight control of an arabinose-inducible promoter, we demonstrated the essentiality of LpxC activity for P. aeruginosa. It was found that compound L-161,240, the most potent inhibitor from the previous study, was active against a P. aeruginosa construct in which the endogenous lpxC gene was inactivated and in which LpxC activity was supplied by the lpxC gene from E. coli. Conversely, an E. coli construct in which growth was dependent on the P. aeruginosa lpxC gene was resistant to the compound. The differential activities of L-161,240 against the two bacterial species are thus the result primarily of greater potency toward the E. coli enzyme rather than of differences in the intrinsic resistance of the bacteria toward antibacterial compounds due to permeability or efflux. These data validate P. aeruginosa LpxC as a target for novel antibiotic drugs and should help direct the design of inhibitors against clinically important gram-negative bacteria.
authors.affiliation: Department of Research Biology, Chiron Corporation, Seattle, WA 98119, USA.
authors.forename: Khisimuzi E
authors.initials: KE
authors.lastname: Mdluli
authors.forename: Pamela R
authors.initials: PR
authors.lastname: Witte
authors.forename: Toni
authors.initials: T
authors.lastname: Kline
authors.forename: Adam W
authors.initials: AW
authors.lastname: Barb
authors.forename: Alice L
authors.initials: AL
authors.lastname: Erwin
authors.forename: Bryce E
authors.initials: BE
authors.lastname: Mansfield
authors.forename: Amanda L
authors.initials: AL
authors.lastname: McClerren
authors.forename: Michael C
authors.initials: MC
authors.lastname: Pirrung
authors.forename: L Nathan
authors.initials: LN
authors.lastname: Tumey
authors.forename: Paul
authors.initials: P
authors.lastname: Warrener
authors.forename: Christian R H
authors.initials: CR
authors.lastname: Raetz
authors.forename: C Kendall
authors.initials: CK
authors.lastname: Stover
mesh_terms: D000581:Amidohydrolases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002384:Catalysis; D017124:Conserved Sequence; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005798:Genes, Bacterial; D006639:Histidine / Q000737:chemistry; D008050:Lipid A / Q000096:biosynthesis; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009154:Mutation; D010080:Oxazoles / Q000737:chemistry / Q000494:pharmacology; D010649:Phenylalanine / Q000737:chemistry; D011401:Promoter Regions, Genetic; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics; D015203:Reproducibility of Results; D017386:Sequence Homology, Amino Acid; D015032:Zinc / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; C101987:L 161240; D008050:Lipid A; D010080:Oxazoles; D010649:Phenylalanine; D006639:Histidine; D000581:Amidohydrolases; C097307:UDP-3-O-acyl-N-acetylglucosamine deacetylase; D015032:Zinc