The mechanism of action of ramoplanin and enduracidin

Fang, Xiao; Tiyanont, Kittichoat; Zhang, Yi; Wanner, Jutta; Boger, Dale L.; Walker, Suzanne

doi:10.1039/b515328j

Cited by 118 publications

(102 citation statements)

References 31 publications

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“…The failure of the sugars to adopt a well-ordered conformation argues against any critical role for them, and in fact they do not contribute to antimicrobial activity or Lipid II binding (16,21,22,26). Indeed, the structurally related depsipeptide antibiotic enduracidin contains no carbohydrate, yet has comparable activity to that of ramoplanin (9,12). Hence, it appears that the sugars contribute mainly to solubility and help define the amphipathic nature of the molecule.…”

Section: Resultsmentioning

confidence: 99%

“…At least three forms are known, A1, A2, and A3; these forms differ in their acyl chain substituents, but possess essentially identical antibiotic activities. Ramoplanins are structurally and functionally related to ramoplanose, which is produced by Actinoplanes strain U.K.-71,903 and which differs from factor A2 by one mannose unit (7), and to enduracidin A and B, which are produced by Streptomyces fungicidicus B5477 (8)(9)(10). This paper focuses on the ramoplanin A2 isomer, the most abundant among the A1-A3 forms; for simplicity's sake, we refer to this isomer as ramoplanin for the remainder of the manuscript.…”

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confidence: 99%

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A crystal structure of a dimer of the antibiotic ramoplanin illustrates membrane positioning and a potential Lipid II docking interface

Hamburger

Hoertz

Lee

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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The glycodepsipeptide antibiotic ramoplanin A2 is in late stage clinical development for the treatment of infections from Grampositive pathogens, especially those that are resistant to first line antibiotics such as vancomycin. Ramoplanin A2 achieves its antibacterial effects by interfering with production of the bacterial cell wall; it indirectly inhibits the transglycosylases responsible for peptidoglycan biosynthesis by sequestering their Lipid II substrate. Lipid II recognition and sequestration occur at the interface between the extracellular environment and the bacterial membrane. Therefore, we determined the structure of ramoplanin A2 in an amphipathic environment, using detergents as membrane mimetics, to provide the most physiologically relevant structural context for mechanistic and pharmacological studies. We report here the X-ray crystal structure of ramoplanin A2 at a resolution of 1.4 Å. This structure reveals that ramoplanin A2 forms an intimate and highly amphipathic dimer and illustrates the potential means by which it interacts with bacterial target membranes. The structure also suggests a mechanism by which ramoplanin A2 recognizes its Lipid II ligand.glycolipodepsipeptide ͉ mechanism ͉ vancomycin resistance

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

A crystal structure of a dimer of the antibiotic ramoplanin illustrates membrane positioning and a potential Lipid II docking interface

Hamburger

Hoertz

Lee

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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“…Cell-wall synthesis comprises the formation of glycan strands (transglycosylation) and peptide cross-links between them (transpeptidation). We thus treated cells with the previously characterized transglycosylation substrate inhibitor ramoplanin (17) and the transpeptidation substrate inhibitor vancomycin (18) [for effective drug treatment we used a lptD4213 mutant (19,20) with increased outer-membrane-permeability]. Here, we propose that the transmembrane cell-wall synthesis complex (yellow) acts in the periplasm (between the cyan outer membrane and peach inner membrane) to polymerize glycan strands (green) and form peptide cross-links (orange) to incorporate the strands into the existing peptidoglycan network, thereby causing the associated MreB filaments (magenta) to rotate in the cytoplasm.…”

Section: Resultsmentioning

confidence: 99%

The bacterial actin MreB rotates, and rotation depends on cell-wall assembly

Teeffelen

Wang

Furchtgott

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

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398

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Bacterial cells possess multiple cytoskeletal proteins involved in a wide range of cellular processes. These cytoskeletal proteins are dynamic, but the driving forces and cellular functions of these dynamics remain poorly understood. Eukaryotic cytoskeletal dynamics are often driven by motor proteins, but in bacteria no motors that drive cytoskeletal motion have been identified to date. Here, we quantitatively study the dynamics of the Escherichia coli actin homolog MreB, which is essential for the maintenance of rod-like cell shape in bacteria. We find that MreB rotates around the long axis of the cell in a persistent manner. Whereas previous studies have suggested that MreB dynamics are driven by its own polymerization, we show that MreB rotation does not depend on its own polymerization but rather requires the assembly of the peptidoglycan cell wall. The cell-wall synthesis machinery thus either constitutes a novel type of extracellular motor that exerts force on cytoplasmic MreB, or is indirectly required for an as-yetunidentified motor. Biophysical simulations suggest that one function of MreB rotation is to ensure a uniform distribution of new peptidoglycan insertion sites, a necessary condition to maintain rod shape during growth. These findings both broaden the view of cytoskeletal motors and deepen our understanding of the physical basis of bacterial morphogenesis.bacterial cytoskeletal dynamics | cell-wall organization | peptidoglycan synthesis | cell growth C ytoskeletal proteins play an important role in bacterial morphogenesis (1). Of the bacterial cytoskeletal proteins, the widely conserved actin homolog MreB is particularly important for bacterial cells to elongate and maintain a rod-like shape. MreB forms polymers that are associated with the cell membrane and distributed along the length of the cell in many rod-shaped bacteria (2). These polymeric MreB structures are essential for the maintenance of rod-like cell shape, as their disruption leads to cell rounding. Although MreB is essential for proper morphogenesis, bacterial cell shape is ultimately determined by the shape of the peptidoglycan cell-wall sacculus, which in turn is controlled by the cell-wall synthesis machinery. The cell wall, which is composed of stiff glycan strands cross-linked by flexible peptide linkers, forms a load-bearing structure that can counteract the intracellular turgor pressure. Cell-wall assembly requires peptidoglycan subunits to be synthesized, polymerized into glycan strands by transglycosylase enzymes, and cross-linked into the existing cell-wall network by transpeptidase enzymes. MreB directly or indirectly associates with a number of proteins that have been implicated in cell-wall assembly, such that MreB is believed to act upstream of the cell-wall assembly machinery to direct the synthesis enzymes to the sites of cell-wall insertion.Previous studies have demonstrated that MreB structures are dynamic in Bacillus subtilis and Caulobacter crescentus (3-7). To date, no motor proteins have been shown to either ...

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“…11 We have recently applied a tailor-made methodology of cell wall digestion and regeneration to the uncommon actinomycete Planobispora rosea, with the aim of improving its production of the thiazolyl peptide antibiotic GE2270 by genome shuffling. 12 In this paper, we have extended the use of this approach to actinomycete species, which produce valuable antibiotics already in clinical use or under development (teicoplanin, 13 A40926-precursor of the semisynthetic dalbavancin-, 14,15 ramoplanin 16 enduracidin 17,18 ) or potentially interesting molecules to be used per se or as scaffold for new drugs 19,20 ( Table 1). The different response to protoplast treatment has been correlated with the diversity of peptidoglycan precursors in representative strains.…”

Section: Introductionmentioning

confidence: 99%

Protoplast preparation and reversion to the normal filamentous growth in antibiotic-producing uncommon actinomycetes

et al. 2010

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Protoplast preparation, regeneration and fusion represent essential tools for those poorly studied biotechnologically valuable microorganisms inapplicable with the current molecular biology protocols. The protoplast production and regeneration method developed for Planobispora rosea and using the combination of hen egg-white lysozyme (HEWL) and Streptomyces globisporus mutanolysin was applied to a set of antibiotic-producing filamentous actinomycetes belonging to the Streptosporangiaceae, Micromonosporaceae and Streptomycetaceae. 10 7 -10 9 protoplasts were obtained from 100 ml of culture, after incubation times in the digestion solution ranging from a few hours to 1 or 2 days depending on the strain. The efficiency of protoplast reversion to the normal filamentous growth varied from 0.1 to nearly 50%. Analysis of cell wall peptidoglycan in three representative strains (Nonomuraea sp. ATCC 39727, Actinoplanes teichomyceticus ATCC 31121 and Streptomyces coelicolor A3(2)) has evidenced structural variations in the glycan strand and in the peptide chain, which may account for the different response to cell digestion and protoplast regeneration treatments. Keywords: antibiotics; bacterial cell wall; glycopeptides; protoplast INTRODUCTIONThe so-called rare or uncommon actinomycetes include a group of filamentous actinomycetes other than Streptomyces spp., which are quite difficult to isolate, cultivate and genetically manipulate. 1 Members of these poorly represented and difficult-to-handle group of microorganisms produce valuable antibiotics. However, the study and the following cost-effective exploitation of uncommon actinomycetes have been slow because of the lack of genetic tools, which hamper strain and product improvement. As mobile genetic elements and conjugation systems are poorly characterized in rare actinomycetes, a crucial methodology to achieve their transformation by exogenous DNA or to recombine whole genomes arising from different cell lines (Whole Genome Shuffling-WGS) is based on protoplast manipulation and fusion. Protoplast preparation and regeneration in Streptomyces spp. were originally reported by Okanishi and co-workers. 2 The method developed for streptomycetes was then applied with uneven success to Micromonospora spp. 3 and Brevibacillus spp., 4 but it soon became clear that the protocol used later was species-or even strain-specific. In other industrially valuable actinomycetes, ad hoc techniques have been developed in some cases, 5-8 but methods endowed with a broad applicability and robustness to be applied for DNA recombination and WGS are not available. A possible explanation for the different response to protocols of protoplast

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The mechanism of action of ramoplanin and enduracidin

Cited by 118 publications

References 31 publications

A crystal structure of a dimer of the antibiotic ramoplanin illustrates membrane positioning and a potential Lipid II docking interface

A crystal structure of a dimer of the antibiotic ramoplanin illustrates membrane positioning and a potential Lipid II docking interface

The bacterial actin MreB rotates, and rotation depends on cell-wall assembly

Protoplast preparation and reversion to the normal filamentous growth in antibiotic-producing uncommon actinomycetes

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