Zeng, Daina Zhao, Jinshi Chung, Hak Suk Guan, Ziqiang Raetz, Christian R. H. Zhou, Pei 2024-01-20T13:03:06Z 2024-01-20T13:03:06Z 2021-09-01 2013-02 0021-9258 https://pubs.kist.re.kr/handle/201004/128426 LpxC, the deacetylase that catalyzes the second and committed step of lipid A biosynthesis in Escherichia coli, is an essential enzyme in virtually all Gram-negative bacteria and is one of the most promising antibiotic targets for treatment of multidrug-resistant Gram-negative infections. Despite the rapid development of LpxC-targeting antibiotics, the potential mechanisms of bacterial resistance to LpxC inhibitors remain poorly understood. Here, we report the isolation and biochemical characterization of spontaneously arising E. coli mutants that are over 200-fold more resistant to LpxC inhibitors than the wild-type strain. These mutants have two chromosomal point mutations that account for resistance additively and independently; one is in fabZ, a dehydratase in fatty acid biosynthesis; the other is in thrS, the Thr-tRNA ligase. For both enzymes, the isolated mutations result in reduced enzymatic activities in vitro. Unexpectedly, we observed a decreased level of LpxC in bacterial cells harboring fabZ mutations in the absence of LpxC inhibitors, suggesting that the biosyntheses of fatty acids and lipid A are tightly regulated to maintain a balance between phospholipids and lipid A. Additionally, we show that the mutation in thrS slows protein production and cellular growth, indicating that reduced protein biosynthesis can confer a suppressive effect on inhibition of membrane biosynthesis. Altogether, our studies reveal a previously unrecognized mechanism of antibiotic resistance by rebalancing cellular homeostasis. English AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC Mutants Resistant to LpxC Inhibitors by Rebalancing Cellular Homeostasis Article 10.1074/jbc.M112.447607 1 JOURNAL OF BIOLOGICAL CHEMISTRY, v.288, no.8, pp.5475 - 5486 JOURNAL OF BIOLOGICAL CHEMISTRY 288 8 5475 5486 N scie scopus 000315342500022 2-s2.0-84874307225 Biochemistry & Molecular Biology Biochemistry & Molecular Biology Article ZINC-DEPENDENT DEACETYLASE GRAM-NEGATIVE INFECTIONS FATTY-ACID BIOSYNTHESIS ESCHERICHIA-COLI PSEUDOMONAS-AERUGINOSA TRANSFER-RNA ANTIBIOTIC-ACTIVITY MEMBRANE-PROTEINS ACTIVE-SITE IN-VIVO LpxC inhibitor Antibiotic resisstance cellular homeostasis lipopolysaccharide biosynthetic pathway