title: Sequence, codon usage and cysteine periodicity of the SerH1 gene and in the encoded surface protein of Tetrahymena thermophila.
abstract: The temperature-regulated SerH1 gene coding for an immunodominant surface glycoprotein (i-Ag H1) of Tetrahymena thermophila has been sequenced. The gene is reproducibly rearranged during macronuclear development and steady state mRNA levels are present at < 36 degrees C. The deduced i-Ag H1 amino acid (aa) sequence is rich in Ser, Thr and Cys, and contains three periods each consisting of 85 aa punctuated by eight Cys with the general formula, CX6CX17CX2CX18CX2CX11CX2CX19 (where X = any aa). Such Cys periodicity is common to ciliate i-Ag. Codon usage in Tt, Paramecium primaurelia and P. tetraurelia i-Ag encoding genes is similar, with approx. 80% A+T in the 3' position which is in marked contrast to the approx. 54% 3' A+T in other ciliate genes.
authors.affiliation: Department of Biology, Cleveland State University, OH 44115, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Deak
authors.forename: F P
authors.initials: FP
authors.lastname: Doerder
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics*; D000954:Antigens, Surface / Q000235:genetics*; D001483:Base Sequence; D016798:Ciliophora / Q000235:genetics; D003001:Cloning, Molecular; D003545:Cysteine / Q000235:genetics; D005786:Gene Expression Regulation; D017125:Genes, Protozoan; D005815:Genetic Code; D008969:Molecular Sequence Data; D005810:Multigene Family; D015800:Protozoan Proteins; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D016808:Tetrahymena thermophila / Q000235:genetics*
chemical_list: D000953:Antigens, Protozoan; D000954:Antigens, Surface; D015800:Protozoan Proteins; C043323:immobilization antigens; D003545:Cysteine