Determination of cDNA and genomic DNA sequences of hevamine, a chitinase from the rubber tree Hevea brasiliensis

Hevamine is a chitinase from the rubber tree Hevea brasiliensis and belongs to the family 18 glycosyl hydrolases. This paper describes the cloning of hevamine DNA and cDNA sequences. Hevamine contains a signal peptide at the N-terminus and a putative vacuolar targeting sequence at the C-terminus which are not present in the mature protein. The gene encoding hevamine contains no introns. Southern hybridization of Hevea brasiliensis DNA with a full-length hevamine cDNA probe showed that there are multiple copies of genes encoding hevamine or hevamine homologues in the Hevea brasiliensis genome. In the lutoid body (vacuolar) fraction of rubber latex only three hevamine components were detected with very similar primary structures, which are probably products of one single locus on the genome. (C) 2001 Editions scientifiques et medicales Elsevier SAS.