Conserved Cys in the Stt7/STN7 kinase. Alignment of the sequences of the Stt7/STN protein kinase from Selaginella moelendorffii (Sm), Physcomitrella patens (Pp), Oryza sativa (Os), Populus trichocarpa (Pt), Arabidopsis thaliana (At), Chlamydomonas reinhardtii (Cr), Chlorella variabilis (Cv), and Micromonas pusilla (Mp). The positions of the conserved C1, C2, C3, and C4 Cys are highlighted in yellow. Note that C3 and C4 are not conserved in C. reinhardtii. Additional Cys residues are highlighted in green. Regions corresponding to the putative transmembrane (TM) and kinase domains are indicated, and invariant residues are marked with an asterisk.