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Publication Abstract from PubMed

The amphomycin derivative tsushimycin has been crystallized and its structure determined at 1.0 A resolution. The asymmetric unit contains 12 molecules and with 1300 independent atoms this structure is one of the largest solved using ab initio direct methods. The antibiotic is comprised of a cyclodecapeptide core, an exocyclic amino acid and a fatty-acid residue. Its backbone adopts a saddle-like conformation that is stabilized by a Ca2+ ion bound within the peptide ring and accounts for the Ca2+-dependence of this antibiotic class. Additional Ca2+ ions link the antibiotic molecules to dimers that enclose an empty space resembling a binding cleft. The dimers possess a large hydrophobic surface capable of interacting with the bacterial cell membrane. The antibiotic daptomycin may exhibit a similar conformation, as the amino-acid sequence is conserved at positions involved in Ca2+ binding.

Structure of the lipopeptide antibiotic tsushimycin.,Bunkoczi G, Vertesy L, Sheldrick GM Acta Crystallogr D Biol Crystallogr. 2005 Aug;61(Pt 8):1160-4. Epub 2005, Jul 20. PMID:16041082^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.