Fig. 1: Natural products containing pyrroloindoline moieties and the crocagin BGC.
From: Unusual peptide-binding proteins guide pyrroloindoline alkaloid formation in crocagin biosynthesis
a, Structures of the calabar alkaloid (physostigmine) and naseseazine. b, Chemical structures of crocagins A (1) and B (2). c, Crocagin BGC found in Chondromyces crocatus CM c5. Genes encoding for putative biosynthetic proteins are shown in orange (dark orange is part of this study); predicted transport proteins, in blue; a regulatory protein, in grey; and the precursor peptide CgnA, in black, which is depicted below the BGC. CgnA is 21 amino acids long and consists of a leader peptide (grey) and a three-amino-acid core peptide (green). Relative sizes of genes and intergenic regions are approximate.
