FIG.1.

Phylogenetic relationship and multiple sequence alignment of StoHK and related sequences. (A) Phylogenetic relationship of StoHK and selected related sequences. The phylogenetic tree was constructed by means of the neighbor-joining method using ClustalX (30). Bootstrap values were calculated from 1,000 replicates and are given at each node. All of the archaeal sequences are shown in boldface, and selected bacterial and eukaryotic sequences are also shown. StoHK (ST2354) is shown in a box. The biochemically characterized GlcNAc kinases are underlined. Accession numbers, annotations, sequence identity to StoHK, and locus names are given in parentheses. The bar indicates 10% amino acid changes between close relatives. (B) Multiple sequence alignment of StoHK, putative homologs Saci_0424 from S. acidocaldarius and SSO3218 from S. solfataricus, and the characterized GlcNAc kinases from mouse, rat, and human. The sequences were aligned using ClustalW (31). Strictly conserved residues are highlighted in black. Highly conserved residues (five out of six sequences are identical) are shown in boxes. Putative ATP-binding motifs are indicated by black lines below the sequences. Cysteine residues conserved among the mammalian GlcNAc kinases are indicated by open or filled triangles below the sequences. Open triangles indicate the cysteine residues involved in the binding of GlcNAc and ATP. Cysteine residues in StoHK are indicated by filled circles above the sequences. The figure was prepared using ESPript (10).