Characterization of ribonucleic acids from Rhizophlyctis rosea zoospores.

The nucleotide composition of ribosomal, soluble and total ribonucleic acids (RNA) from the zoospores of Rhizophlyctis rosea was determined. The base ratios for ribosomal, soluble, and total RNA were 49.16, 51.79 and 49.97 moles percent, guanylic acid (G) and cytidylic acid (C) respectively. The distribution of the nucleotides in ribosomal RNA differed slightly from those determined in other fungi and microorganisms. The amount of uridylic acid in soluble RNA was very high, while the GC content was unexpectedly low. Ribosomes were characterized with respect to their mean sedimentation coefficient, under high magnesium (0.01 M) concentrations, in the analytical ultracentrifuge, and by a linear sucrose-density gradient centrifugation. The particles had an average of 82 S by the sucrose-density gradient method, and an average of 78 S by the analytical ultracentrifugation technique.