Alu elements in a Plasmodium vivax antigen gene.

Plasmodium vivax is a very common human malaria parasite but it is poorly characterized at the molecular level. Here, we describe the isolation and characterization of an antigen coding gene of P. vivax which contains Alu elements. This gene, called Pv-Alu, is expressed during the erythrocytic phase of the parasite. The encoded 200 amino acid long polypeptide is highly hydrophobic, contains transmembrane domains, and is rich in leucine (19.4%), serine (15.9%), proline (15.4%) and phenylalanine (15.4%). The 5'-untranslated region and part of the 3'-end coding region of Pv-Alu show significant homology to different Alu families. The presence of Alu elements in the coding region of a parasite antigen gene is significant from a functional and evolutionary viewpoint.