Extended Data Fig. 4: Sequence coverage for five enamel-specific proteins across Pleistocene samples and recent human controls.

For each protein, the bars span protein positions covered, with positions remapped to the human reference proteome. The top row indicates the position of a selection of known MMP20 and KLK4 cleavage products of the enamel-specific proteins AMELX⁵⁵, AMBN⁵² and ENAM⁵⁶. Several in vivo proteolytic degradation fragments of ENAM share the same N terminus, but have unknown C termini⁵³. Dotted line for AMBN indicates a putative cleavage product based on known MMP20 (squares) and KLK4 (circles) in vivo cleavage positions. For AMTN, serines (S) at positions 115 and 116 (indicated by asterisks) are conserved among vertebrates and involved in mineral-binding²¹. Additional cleavage products as well as MMP20 and KLK4 cleavage sites are known in all enamel-specific proteins. SK339¹⁶ and Ø1952 are two recent human control samples (Methods). AA, amino acids; Steph., Stephanorhinus⁶; TRAP, tyrosine-rich amelogenin polypeptide.