Discovery of Six Ramoplanin Family Gene Clusters and the Lipoglycodepsipeptide Chersinamycin**

Abstract

Ramoplanins and enduracidins are peptidoglycan lipid intermediate II-binding lipodepsipeptides with broad-spectrum activity against methicillin-and vancomycin-resistant Grampositive pathogens. Targeted genome mining using probes from conserved sequences within the ramoplanin/enduracidin biosynthetic gene clusters (BGCs) was used to identify six microorganisms with BGCs predicted to produce unique lipodepsipeptide congeners of ramoplanin and enduracidin. Fermentation of Micromonospora chersina yielded a novel lipoglycodepsipeptide, called chersinamycin, which exhibited good antibiotic activity against Gram-positive bacteria (1-2 μg/ mL) similar to the ramoplanins and enduracidins. The covalent structure of chersinamycin was determined by NMR spectroscopy and tandem mass spectrometry in conjunction with chemical degradation studies. These six new BGCs and isolation of a new antimicrobial peptide provide much-needed tools to investigate the fundamental aspects of lipodepsipeptide biosynthesis and to facilitate efforts to produce novel antibiotics capable of combating antibiotic-resistant infections.

Synthetic ramoplanin analogues are accessible by effective incorporation of arylglycines in solid-phase peptide synthesis

“…1 Selected arylglycine containing bioactive compounds up to 3000 Da including both small molecules and peptides. (A) Molecules boxed in green (cephalexin, 7 vancomycin, 8,9 arylomycin A2, 10,11 teicoplanin, 8,9 corbomycin, 15 feglymycin 12,13 and ramoplanin A2 and aglycone 14,15 ) are either natural products or derived from natural products (semi-synthetics); molecules boxed in blue (JNJ-A07, 20 the Related Orphan Receptor-gt (RORgt) inverse agonist 21 and pasireotide 22 ) are synthetic compounds. (B) Chemical structure of ramoplanin A2 (RA2) and aglycone (RAglywithout the two D-mannoses).…”

Micromonospora: A Prolific Source of Bioactive Secondary Metabolites with Therapeutic Potential

“…210,211 Genome mining using conserved sequences of the ramoplanin/enduracidin BGCs in M. chersina DSM 44151 as the targeted probe led to the isolation of the lipoglycodepsipeptide antibiotic 220. 212 The LC/MS profiling of the gut bacterium Micromonospora sp. UTJ3 from the carrion beetle Silpha perforata afforded lipodepsipeptide 221, which displayed specific activity against M. tuberculosis mc 2 6230.…”

“…schwarzwaldensis strain HKI0641. , Genome mining using conserved sequences of the ramoplanin/enduracidin BGCs in M. chersina DSM 44151 as the targeted probe led to the isolation of the lipoglycodepsipeptide antibiotic 220 . The LC/MS profiling of the gut bacterium Micromonospora sp.…”

Bioactive Lipodepsipeptides Produced by Bacteria and Fungi

“…Ramoplanins A1, A2, A3 and ramoplanose ( 95 – 98 , Figure 11 ) and the enduracidins A and B ( 99 and 100 , Figure 10 ) were isolated from Actinoplanes ATCC 33076 [ 109 , 110 ] and from Streptomyces fungicidicus B5477, respectively [ 111 ]. Their structures are quite close [ 112 ]. Their antibiotic activity is based on their ability to avoid peptidoglycan (PG) cross-link generation inducing bacterial death consequent to osmotic lysis of the cell wall.…”