title: Structure and sequence of the H surface protein gene of Paramecium and comparison with related genes.
abstract: The serotype H immobilization antigen (H i-ag) gene of Paramecium tetraurelia was isolated from a genomic library by screening with the H i-ag transcript. The gene is 7.5 kb long and contains no introns. Similar to other i-ag genes, it does not undergo rearrangement or duplication upon expression. In contrast, only the H i-ag gene appears to be non-adjacent to a telomere. Sequence comparisons between the H, A, and C i-ag genes of stock 51 and the G i-ag gene of stock 156 identify conserved upstream sites and extensive homology in the 3' non-coding region. Several of these sites may be involved in regulating the expression of the i-ags. Segments of amino acid homology among these genes are also predicted by the DNA sequences.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan; D000954:Antigens, Surface / Q000235:genetics*; D001483:Base Sequence; D003062:Codon; D005796:Genes; D010247:Paramecium / Q000235:genetics*; D015800:Protozoan Proteins; D014158:Transcription, Genetic
chemical_list: D000953:Antigens, Protozoan; D000954:Antigens, Surface; D003062:Codon; D015800:Protozoan Proteins; C043323:immobilization antigens