Positions of selected toxic fragments relative to the structure of genes of the PI kinase family. Names of the selected genes and protein lengths (in amino acids) are indicated. Coordinates of the toxic fragments selected in this work and of known toxic domains (see text) are also given. Conserved domains in the proteins have been positioned using the NCBI CD-Search program  (see Materials and methods). Domain abbreviations: FAT (pfam 00259) is named after FRAP, ATM and TRRAP, which are human homologs of yeast TOR, TEL1 and TRA1, respectively; PI3Kc (smart00146) is the PI kinase catalytic domain; FATC (pfam02260.11) is named after FRAP, ATM, TRRAP carboxy-terminal region. Complete COG5032 TEL1 (2,105 residues) spans the carboxy-terminal regions of the four proteins. The drawing is not to scale.