SEQUENCE AND GENOMIC ORGANIZATION OF THE HSP70 GENES OF LEISHMANIA-AMAZONENSIS

The sequence and genomic organization of hsp70 genes in Leishmania ama zonensis were examined. Maps of overlapping cosmid clones revealed tha t seven L. amazonensis hsp70 genes are organized into a 24-kb locus co ntaining 3.5-kb tandem repeats. Cosmids covering a different chromosom al region indicated that an eighth hsp70 sequence is located at a dist ant site. Southern blot data suggested the existence of additional hsp 70 genes or pseudogenes. One complete 3.5-kb genomic repeat unit, incl uding coding and intergenic regions, was sequenced. The predicted L. a mazonensis HSP70 protein had approximately 95% sequence identity with Leishmania donovani or Leishmania major HSP70, 81-85% identity with tr ypanosome HSP70, and 68 or 72% identity with human HSP70 or HSP70 cogn ate, respectively. The GGMP tetrapeptide repeal found in other trypano somatid HSP70 proteins is absent from the L. amazonensis sequence. Int ergenic sequences of L. amazonensis and L. major differed mainly in th e presence of short gaps in the L. amazonensis sequence. Potential reg ulatory heat shock elements were identified in the upstream sequence. Several cDNA clones were also isolated, and two different poly(Af addi tion sites 100 nucleotides apart were identified.