Protein sequences comparison among vertebrate TWIST family members. Alignment of amino acid sequences encoded by the Twist gene from different species showed beside the well known basic Helix-Loop-Helix (bHLH) motif, conservation in four additional protein regions. NLS1 and NLS2 mark putative nuclear localization signals. Gaps are indicated as hyphens. Black boxes indicate identical amino acids which are present in all species. Grey boxes are present in identical amino acid in six species and light grey boxes in five species, respectively. Alignment was generated by ClustalW.