Figure 7.

Sequence diversity between closely related molecular species. Some molecular species differ by only a few residues, e.g., (A) while others exhibit pronounced sequence variation, e.g., (B–D) Sequence differences are highlighted by red boxes. Common sequence traits (indicated by blue boxes) are found in closely related precursors. (E) Differences in the residues forming the CCK structural motif (green boxes). Additional cysteines are found in loop 2 of valt1-FS3U and loop 6 of prc-vitri60-RS1V. The cyclisation-enabling N/D residues are absent in loop 6 of valt1-FS3U. Vima1-FA1V lacks a cysteine residue in loop 6, which is elongated. (F) and (G). Emergence of a cyclic backbone in the Möbius and bracelet lineages, respectively. Both lineages exhibit large sequence variation in the C-terminal loop 6. (H,I) Proline-rich sequence regions (indicated by yellow boxes).