Figure 2.

The six ts alleles each contain a single mutation in the kinase domain. The amino acid sequence of the Mps1p protein kinase domain is shown. Above the sequence, the 11 subdomains of the kinase domain and the residues conserved among the family of serine-threonine kinases are listed (Ser/Thr; see Hanks et al., 1988). Uppercase letters indicate highly conserved residues, and lowercase letters indicate less well conserved ones. The italicized E in subdomain V denotes a residue conserved in some dual-specificity kinases (Lindberg et al., 1992). The amino acid changes caused by each mps1 mutation and its corresponding allele number are noted above the Mps1p sequence, and the altered residue in Mps1p is underlined. Below the Mps1p sequence are those for the kinase domains of esk, PYT/TTK, and PPK1 (Douville et al., 1992; Lindberg et al., 1992; Kwart, personal communication). Identity between Mps1p and the other kinases is indicated by black boxes, and similarity is indicated by gray boxes. A homolog of MPS1 has also been found in Schizosaccharomyces pombe (He and Sazer, personal communication) but is not shown here. The sequences given here begin at the following amino acid numbers: Mps1p, position 437; esk, position 521; PYT/TTK, position 506; PPK1, position 144.