PMEL Mutations Make Functional Amyloid Pathogenic Figure 8. The PKDDLLVT secondary mutation found in the Smoky chicken PMEL prevents delivery of TMinsWAP mutant hPMEL to fibrillogenic compartments. A. Sequence of PKD domain residues 245–280 in wild-type and mutant hPMEL. The PMEL gene in the Smoky chicken harbors an in-frame deletion that eliminates four amino acids from the PKD domain, corresponding to LVVT in hPMEL (PKDDLLVT), in addition to the PLoS Genetics | www.plosgenetics.org 11 September 2011 | Volume 7 | Issue 9 | e1002286