Fig. 2. Localization of regions involved in MyoA and MTIP interaction. (A) The putative neck (amino acids 842-902) and tail (amino acids 903-917) domains of P. yoelii MyoA were cloned together or separately into the Gal4 DNA binding domain vector pAS2.1. The resulting plasmids were transformed into yeast strain PJ69-4a, containing the full length P. yoelii MTIP in the Gal4 activation domain vector (pAD-MTIP), and assayed for their ability to grow in the absence of histidine or adenine (growth is indicated as +; no growth as -). Only the tail domain of MyoA was necessary and sufficient for interaction with MTIP. (B) N- and C-terminal deletions of P. yoelii MTIP were constructed in the Gal4 activation domain vector, transformed into yeast strain PJ69-4a containing pAS2.1-MyoA (amino acids 842-917) and assayed as described above. The minimal interacting region located to amino acids 80-204. Further N-terminal deletion of 15 amino acids or C-terminal deletion of 15 amino acids abrogated interaction. (C) Site-directed mutagenesis of the basic motif within the tail of P. yoelii MyoA in the vector pAS2.1-MyoA. Plasmids were analyzed as described in A. Change of RKRAAA or RKRAAR abrogated interaction. ^*Values for ß-galactosidase activity are the mean of three independent cultures assayed in duplicate±s.d.