Fig. 1. Alignment of several mammalian CA IV enzymes with two mosquito CA IV-like isoforms. The leucine-rich signal sequences are displayed in all aligned isoforms (red), along with the 3 essential zinc-binding histidines (blue), and cysteine residues (green) that form disulfide bonds. The reduced activity in rodent CA IVs is caused by the glycine-69 mutation to glutamine (orange; Tamai et al., 1996a,b), which the mosquitoes do not display. Important conserved residues are boxed. The position of mammalian signal sequence cleavage is shown (vertical line) and therefore the following amino acid is residue #1 in the functional protein. The peptide sequence used for antibody generation is also displayed (violet horizontal box). Asterisks, identical residues; dots, conserved residues. Broken orange lines mark the shortened active site region within the two mosquito sequences when compared to mammalian CA IV enzymes.