Saccharomyces cerevisiae A49 is a specific subunit associated with RNA polymerase I (Pol I) in eukaryotes. Pol I maintains transcription activities in A49 deletion mutants. However, such mutants are deficient in transcription activity at low temperatures. Deletion analysis of the fusion yeast homolog indicate that only the C-terminal two thirds are required for function. Transcript analysis has demonstrated that A49 is maximising transcription of ribosomal DNA [1].

1: The fission yeast RPA51 is a functional homolog of the budding yeast A49 subunit of RNA polymerase I and required for maximizing transcription of ribosomal DNA. Nakagawa K, Hisatake K, Imazawa Y, Ishiguro A, Matsumoto M, Pape L, Ishihama A, Nogi Y; Genes Genet Syst 2003;78:199-209. PMID:12893961