New antibiotics are needed, particularly those that can be considered as new chemical entities and have novel targets relative to the current, clinical armament of antibiotics. Highly modified nucleoside antibiotics that inhibit bacterial translocase I (TL1) involved in cell wall biosynthesis fit both these descriptions, and have excellent potential in part because they are (i) nanomolar inhibitors of TL1, (ii) inhibit a target that has been proven to be essential for the survival of most, if not all, bacteria, (iii) are effective antibiotics in both in vitro and in vivo models, and (iv) have no apparent toxicity in mice. We have defined the biosynthetic mechanism leading to the core disaccharyl-nucleoside structure of several promising nucleoside antibiotics including A-90289 from Streptomyces sp. SANK 60405, muraminomicin from Streptosporangium sp, and muraymycin from Streptomyces sp. LL-AA896 using a combined in vivo and in vitro approach. The results have defined a multi-enzyme pathway highlighted by divergence from the primary building block UMP and reconvergence to form the core nucleoside. This data was utilized to scan the wealth of genomic information to identify a new lead antibiotic, sphaerimicin, which was isolated and revealed to share the nucleoside core structure but have several unique features including a dihydroxylated piperidine ring of unknown origin. We will now accomplish the following specific aims: (i) to define the mechanism for the attachment of the 3-amino-3-carboxypropyl (3A3CP) moiety that generates the last, shared intermediate in the biosynthesis of A-90289, muraminomicin, muraymycin, and sphaerimicin, which is hypothesized to occur via a new enzyme strategy catalyzed by a pyridoxal-5?-phosphate-dependent protein and (ii) to delineate the biosynthetic mechanism for divergence from the last, shared intermediate to generate unique, nucleoside core scaffolds that are further decorated by fatty acids, polyketides, nonribosomal peptides, and/or saccharides. A biosynthetic mechanism for the diazepanone ring for A-90289 and the highly unusual fused piperidine ring system in sphaerimicin will be defined.

Public Health Relevance

Diseases caused by multidrug resistant bacteria are becoming a significant threat to human health worldwide. The goal of this proposal is to study nucleoside antibiotics that represent a new structural class of antibiotics, have a different mode of action than clinically used antibacterial drugs, are effective antibiotics in both in vitro and in vivo models, and are in general not toxic to mice.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI087849-06
Application #
9266345
Study Section
Synthetic and Biological Chemistry B Study Section (SBCB)
Program Officer
Xu, Zuoyu
Project Start
2011-06-15
Project End
2021-04-30
Budget Start
2017-05-01
Budget End
2018-04-30
Support Year
6
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of Kentucky
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
939017877
City
Lexington
State
KY
Country
United States
Zip Code
40526
Koppermann, Stefan; Cui, Zheng; Fischer, Patrick D et al. (2018) Insights into the Target Interaction of Naturally Occurring Muraymycin Nucleoside Antibiotics. ChemMedChem 13:779-784
Cui, Zheng; Wang, Xia-Chang; Liu, Xiaodong et al. (2018) Self-Resistance during Muraymycin Biosynthesis: a Complementary Nucleotidyltransferase and Phosphotransferase with Identical Modification Sites and Distinct Temporal Order. Antimicrob Agents Chemother 62:
Huang, Ying; Liu, Xiaodong; Cui, Zheng et al. (2018) Pyridoxal-5'-phosphate as an oxygenase cofactor: Discovery of a carboxamide-forming, ?-amino acid monooxygenase-decarboxylase. Proc Natl Acad Sci U S A 115:974-979
Cui, Zheng; Liu, Xiaodong; Overbay, Jonathan et al. (2018) Enzymatic Synthesis of the Ribosylated Glycyl-Uridine Disaccharide Core of Peptidyl Nucleoside Antibiotics. J Org Chem 83:7239-7249
Goswami, Anwesha; Liu, Xiaodong; Cai, Wenlong et al. (2017) Evidence that oxidative dephosphorylation by the nonheme Fe(II), ?-ketoglutarate:UMP oxygenase occurs by stereospecific hydroxylation. FEBS Lett 591:468-478
Liu, Xiaodong; Jin, Yuanyuan; Cai, Wenlong et al. (2016) A biocatalytic approach to capuramycin analogues by exploiting a substrate permissive N-transacylase CapW. Org Biomol Chem 14:3956-62
Kulkarni, Aditya; Zeng, Yu; Zhou, Wei et al. (2016) A Branch Point of Streptomyces Sulfur Amino Acid Metabolism Controls the Production of Albomycin. Appl Environ Microbiol 82:467-77
Liu, Xiaodong; Jin, Yuanyuan; Cui, Zheng et al. (2016) The Role of a Nonribosomal Peptide Synthetase in l-Lysine Lactamization During Capuramycin Biosynthesis. Chembiochem 17:804-10
Cai, Wenlong; Wang, Xiachang; Elshahawi, Sherif I et al. (2016) Antibacterial and Cytotoxic Actinomycins Y6-Y9 and Zp from Streptomyces sp. Strain Gö-GS12. J Nat Prod 79:2731-2739
Cai, Wenlong; Goswami, Anwesha; Yang, Zhaoyong et al. (2015) The Biosynthesis of Capuramycin-type Antibiotics: IDENTIFICATION OF THE A-102395 BIOSYNTHETIC GENE CLUSTER, MECHANISM OF SELF-RESISTANCE, AND FORMATION OF URIDINE-5'-CARBOXAMIDE. J Biol Chem 290:13710-24

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