Fig. 5: Parallel growth of peptides at various positions on RNA, effect of base pairing and RNA–peptide synthesis cycles.
From: A prebiotically plausible scenario of an RNA–peptide world
a, Coupling of oligonucleotides containing multiple donor or acceptor units (EDC/Sulfo-NHS, see reaction condition a in Fig. 2). b, Annealing followed by coupling (EDC/Sulfo-NHS, see reaction condition a in Fig. 2) of an acceptor strand with donor strands of different length (left) or base sequence (right). c, Two RNA–peptide synthesis cycles with a third coupling step using a 2'-OMe acceptor strand and performed under one-pot conditions with intermediary filtration to remove the remaining activator (coupling: DMTMM·Cl, see reaction condition b in Fig. 2; cleavage: 100 mM acetate buffer pH 4, 100 mM NaCl, 90 °C, 24 h; MES buffer pH 6 was used in the first cleavage reaction). HPLC chromatograms show the crude mixtures of the coupling and cleavage reactions. Peaks of RNA strands are coloured as in the reaction scheme. MALDI-TOF data (negative mode) of the isolated products are given.
