Structures of MPL-P and MPL-K. Amino acid sequences of the C-terminal half of the transmembrane region and the intracellular region are shown for MPL-P and MPL-K together with the putative correct MPL-K (MPL-Kc). The underlined sequence indicates the C-terminal half of the transmembrane domain. The amino acid sequences that are common between MPL-P and MPL-K and between MPL-K and MPL-Kc are indicated by vertical lines. The numbers on both sides are the amino acid number from the first methionine.