Eukaryotic pantothenate kinase is a ribonuclease H-like kinase. Multiple sequence alignment for representative sequences of the pantothenate kinase family and two related ribonuclease H-like families with known structure (2-hydroxyglutaryl-CoA dehydratase component A (PDB|1hux ) and hexokinase I (PDB|1dgk )) is shown. The PHOSPHATE 1, PHOSPHATE 2, and ADENOSINE motifs are indicated by dashed boxes. Abbreviations of species names are as follows: Af Acidaminococcus fermentans, At Arabidopsis thaliana, Bc Bacillus cereus, Ca Clostridium acetobutylicum, Ce Caenorhabditis elegans, Dm Drosophila melanogaster, En Emericella nidulans, Hs Homo sapiens, Mm Mus musculus, Mt Methanothermobacter thermautotrophicus, Pa Pichia angusta, Ta Thauera aromatica, Tt Thermoanaerobacter tengcongensis. Locations of predicted (gi|4191500) and observed (PDB|1hux_A, PDB|1dgk_N) secondary structure elements (E, β-strand; H, α-helix) are marked above the sequences in italics and normal font, respectively.