1Q71:
reference: Microcin J25 has a threaded sidechain-to-backbone ring structure and not a head-to-tail cyclized backbone., Rosengren KJ, Clark RJ, Daly NL, Goransson U, Jones A, Craik DJ, J Am Chem Soc 2003 Oct 15;125(41):12464-74. PMID: 14531690

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