Nucleic Acids Research, 1984, Vol. 12, No. 9 3951-3958
© 1984
MOLECULAR BIOLOGY |
Highly conserved 5S ribosomal RNA sequences in four rust fungi and atypical 5S rRNA secondary structure in Microstroma juglandis*
Celltech Ltd, 244250 Bath Road, Slough SL1 4DY, Berks, UK
**To whom the correspondence should be addressed
Received February 27, 1984. Revised April 10, 1984. Accepted April 10, 1984.
The 5S ribosomal RNA nucleotide sequences of five basidiomycetous fungi, Coleosporium tussilaginis, Gymnosporangium clavariaeforme, Puccinia poarum, Endophyllum sempervivi and Microstroma juglandis were determined. Despite high differentiation in their host spectra the four rust species are highly conserved with respect to their 5S rRNA sequences, which fit with the basidiomycete cluster 5 described by Walker and Doolittle (1). The sequences obtained from the first three rust fungi were proven to be identical while the sequence from Endophyllum sempervivi showed two base substitutions compared with the other rust fungi. The Microstroma juglandis 5S rRNA sequence differs from all other basidiomycete 5S rRNA sequences published so far in respect to its secondary structure which shows an atypical CCA loop in helix D, but it reveals typical basidiomycetous signature nucleotides. Therefore Microstroma juglandis represents a cluster of its own within the Basidiomycetes. A dendrogram was constructed based on Kimura's "Neutral Theory of Molecular Evolution".
* Part 33 of a series "Studies in Heterobasidiomycetes" of the Institut für Biologie I, Lehrstuhl Spezielle Botanik, Universität Tübingen.