Figure 4.

Global amino acid alignment of CA XII and CA IX proteins obtained by using the clustalw alignment tool as provided by the ExPasy server (http://expasy.hcuge.ch/sprot/scnpsite.html). The overall identity is 35.8%, and the identical residues are marked by ∗ below the sequence. The three essential Zn-liganded histidine residues are marked by Zn symbols above them. The short cytoplasmic domains are boxed with histidine, threonine, serine, and tyrosine residues underlined. The ideograms depicting the domain structure of the genes are positioned above the alignment. SP, signal peptide; CA, carbonic anhydrase domain; TM, transmembrane peptide; CTD, cytoplasmic domain; PG, proteoglycan domain.