Nucleotide sequences of the yeast recessive suppressor gene SUP1 and one of its mutant alleles (supl-ts36) are compared. One open reading frame is found in the gene able to code 438 amino acid residues. The reading frame is not interrupted by introns. Mutant allele supl-ts36 contains one nucleotide change at position + 101 (T----C) inducing the exchange of leucine on serine in N-terminal part of the polypeptide product. The homology between the structure of SUP1 gene and two groups of proteins is found (1.tRNA-binding or nucleotide-binding proteins; 2. mitochondrial proteins coded by mitochondrial genome). The size of transcript for SUP1 gene is 1600 nucleotides corresponding to the coding region of the gene. For SUP2 gene two stable transcripts are found corresponding to approximately 2500 and approximately 1400 nucleotides. The homology between SUP1 and SUP2 genes is not found. The absence of splicing for both SUP1 and SUP2 genes transcripts is demonstrated in the experiments with RNA2 conditional mutants with impaired splicing.