Figure 1.

Distribution of PLP1 gene mutations identified in our series of patients with PLP1-related disorders in relation to the proposed model* of the tetra-span proteolipid proteins, PLP and DM20. With respect to the missense mutations reported here, the amino acid residues affected by novel mutations are shown in purple, whereas residues harbouring previously reported mutations are given in green. The four predicted transmembrane domains (TMD1-4) are depicted, the first and last amino acids being indicated for each TMD. The PLP1-specific region (which is absent from DM20) is denoted by a dotted line. The locations of the two disulfide bridges (Cys184-Cys228 and Cys201-Cys220) within loop B (LB) are marked "S--S". The double arrow indicates the relative placement of the exon-exon (Ex) junctions superimposed upon the PLP1 protein. *model according to Popot et al, [36] and Weimbs and Stoffel [37]