Structure of antibacterial peptide microcin J25: A 21-residue lariat protoknot

Marvin J. Bayro, Jayanta Mukhopadhyay, G. V.T. Swapna, Janet Y. Huang, Li Chung Ma, Elena Sineva, Philip E. Dawson, Gaetano T. Montelione, Richard H. Ebright

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The antibacterial peptide microcin J25 (MccJ25) inhibits bacterial transcription by binding within, and obstructing, the nucleotide-uptake channel of bacterial RNA polymerase. Published covalent and three-dimensional structures indicate that MccJ25 is a 21-residue cycle. Here, we show that the published covalent and three-dimensional structures are incorrect, and that MccJ25 in fact is a 21-residue "lariat protoknot", consisting of an 8-residue cyclic segment followed by a 13-residue linear segment that loops back and threads through the cyclic segment. MccJ25 is the first example of a lariat protoknot involving a backbone-side chain amide linkage.

Original languageEnglish (US)
Pages (from-to)12382-12383
Number of pages2
JournalJournal of the American Chemical Society
Issue number41
StatePublished - Oct 15 2003

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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    Bayro, M. J., Mukhopadhyay, J., Swapna, G. V. T., Huang, J. Y., Ma, L. C., Sineva, E., Dawson, P. E., Montelione, G. T., & Ebright, R. H. (2003). Structure of antibacterial peptide microcin J25: A 21-residue lariat protoknot. Journal of the American Chemical Society, 125(41), 12382-12383.