cDNA cloning of Entamoeba histolytica histone H3

E. histolytica has an unusual nuclear structure. Although nucleosome-like particles were observed, no information about histones was available so far. In this paper we describe a cDNA clone with significant homology to H3 histones that was isolated from a lambda Zap library of pathogenic E. histolytica. The complete cDNA encodes a 15 kDa polypeptide, which is shorter by one residue than the human homologue. The amino acid sequence has only 69% identity with human H3.3 histone. Our results indicate that this divergence may contribute to the unusual chromatin structure of E. histolytica.