THE STRUCTURE OF THE CALMODULIN GENE OF PLASMODIUM-FALCIPARUM

The calmodulin gene and its flanking sequences from the malaria parasite, Plasmodium falciparum, have been analysed. The structure of this gene is unique amongst other known calmodulin genes. It exists as a single copy on chromosome 14 and has a single intron. The nucleotide sequence of this 4-kb region suggests the existence of three transcriptional units, each separated by a highly A+T-rich sequence. Sequences controlling gene expression might be expected to occur in these intergenic regions. The predicted protein sequences suggest that these other genes are transcribed in different orientations. Primer extension studies suggest that calmodulin mRNA has a major start site 62 bases upstream of the initial ATG. The calmodulin gene possesses consensus eukaryotic TATA, CAAT box, polyadenylation and splice junction sequences. This is the first detailed report of the DNA sequence surrounding a housekeeping gene in P. falciparum.