We have isolated and characterized a Neurospora crassa gene homologous to the yeast CYH2 gene encoding L29, a cycloheximide sensitivity-conferring protein of the cytoplasmic ribosome. The cloned Neurospora gene was isolated by cross-hybridization to CYH2. It was sequenced from both cDNA and genomic clones. The coding region is interrupted by seven intervening sequences. Its deduced amino acid sequence shows 70% homology to that of yeast ribosomal protein L29 and 60% homology to that of mammalian ribosomal protein L27', suggesting that the protein has an important role in ribosomal function. The pattern of codon usage is highly biased, consistent with high translation efficiency. There is a single copy of this gene in N. crassa, and R. Metzenberg and coworkers have mapped its genetic location to the vicinity of the cyh-2 locus.