An 85-kilodalton surface antigen gene family of Trypanosoma cruzi encodes polypeptides homologous to bacterial neuraminidases

摘要: Abstract We have determined the sequence of a cDNA (Tt34cl) encoding Trypanosoma cruzi trypomastigote stage-specific 85-kDa surface glycoprotein (gp85). Within peptide Tt34cl are two 8-amino acid motifs, Ser-X-Asp-X-Gly-X-Thr-Trp, that characteristic bacterial neuraminidases. Analysis predicts presence an amino-terminal signal and hydrophobic carboxy-terminus is probably replaced by glycosyl phosphatidylinositol membrane anchor. Gp85 encoded extensive multigene family distributed throughout genome can be divided into subsets on basis oligonucleotide hybridisation patterns. By sequencing products polymerase chain reaction (PCR) amplification 5′ end gp85 mRNA we show multiple copies gene transcribed simultaneously in trypanosome population. Comparison PCR clones another showed highly conserved region first methionine extending 180 nt coding sequence. Insertions point mutations were observable outside these homologous sequences demonstrating variant nature mRNAs.