Amino acid sequence alignment of different domains of the P. vivax HSP (PVHSP28) with other proteins obtained by using the FASTA program and the EMBL database. HTPX, small heat shock protein containing the metalloprotease motif; HTPXEco, protein from E. coli (accession no. P23894); HTPXHin, protein from Haemophilus influenzae (accession no. P44840); HTPXAae, protein from Aquifex aeolicus (accession no. 2984218); HTPXPho, protein from Pyrococcus horikoshii (accession no. BAA 30357); HTPXMja, protein from Methanococcus jannaschii (accession no. H64509); HTPXSgo, protein from Streptococcus gordonii (accession no. 2407215); HTPXMtu, protein from Mycobacterium tuberculosis (accession no. CAB08997); HTPXBsu, protein from Bacillus subtilis (accession no. CAB 13222); HTPXHpy, protein from Helicobacter pylori (accession no. AA007972.1); HTPXMth, protein from Methanobacterium thermoautotrophicum (accession no. 2621646); HTPXAfl, protein from Archaeoglobus fulgidus (accession no. 2650402); HTPXSsp, protein from a Synechocystis sp. (accession no. BAA18200); STE24, yeast homologue of HTPX (accession no. NP005848.1); HSTE24, human homologue of HTPX (accession no. 300769 and AF064867). The amino acid residues identical to those in the PVHSP of P. vivax are shown in boldface. The amino acids involved in metal binding are marked with an asterisk, and those involved in the catalytic activity are marked with a plus sign. Dashes indicate the absence of an amino acid residue at that position. The shaded amino acids represent the consensus (HEXXH and EXXXD) metalloprotease motif. Numbers on left of each sequence indicate the amino acid residue number in that protein.