AN AMPLIFIED DNA ELEMENT IN LEISHMANIA ENCODES POTENTIAL INTEGRAL MEMBRANE AND NUCLEOTIDE-BINDING PROTEINS

LD1 is a 27.5-kb sequence that occurs in an approx. 2.2-Mb chromosome in all species and strains of Leishmania. In Leishmania infantum MHOM/ BL/67/ITMAP263, LD1 is also present as an inverted dimeric repeat in m ulticopy, 55-kb circular molecules. Sequence analysis of a 7873-nt seg ment derived from the circular DNA reveals 4 open reading frames (ORFs ) with potential protein coding function. One ORF predicts a protein w ith an ATP/GTP binding site motif. Another ORF predicts a protein with 10-12 potential membrane-spanning domains, suggesting that it encodes an integral membrane protein. This protein also has homology with tha t predicted by the ESAG10 gene of Trypanosoma brucei.