Sequence alignments of the signature sequences present in NBD1 and spacer domain of Arabidopsis Hsp100 and related protein members. The consensus sequences described by are indicated at the top of the boxes. Large case letters represent the corresponding amino acid residues in the 1-letter code; x is any amino acid residue, whereas h stands for any of the hydrophobic amino acid residues, ie, isoleucine, leucine, valine, methionine, phenylalanine, or tyrosine. Note that in some cases these consensus motifs do not reflect the reality of the Arabidopsis Hsp100 proteins (see examples of signature sequence II and Walker B motif in NBD2)