ANALYSIS OF THE GENOMIC SEQUENCE ENCODING THE 29-KDA CYSTEINE-RICH PROTEIN OF ENTAMOEBA-HISTOLYTICA

By analyzing cDNA and genomic clones coding for the 29-kDa cysteine-ri ch protein of Entamoeba histolytica, substantial sequence differences were found to the 5'-end of a previously described full-length cDNA co ding for the same protein (Reed et al., 1992), which was reported to c ontain an untranslated 5'-sequence of at least 171 nucleotides, unusua l for E. histolytica cDNAs. We found evidence that the cDNA published by Reed et al. (1992) represents a hybridclone composed of two unrelat ed sequences and that the gene coding for the 29-kDa molecule comprise s all of the features typical for E. histolytica genes. A data base an alysis revealed substantial sequence homology of the 29-kDa protein to a class of polypeptides found in prokaryotic organisms that may be in volved in the inactivation of hydrogen peroxide.