Characterization of ribosomes from Neurospora crassa.

Ribosomes isolated from growing hyphae of Neurospora crassa contain 53 per cent protein and 47 per cent RNA and have a sedimentation coefficient of 81S at 20 degrees C and infinite dilution. These ribosomes are stable at pH 7.4 in the presence of 0.01 M and 0.002 M MgCl(2) but undergo a dissociation into smaller particles if the MgCl(2) concentration is lowered to 0.0001 M. Two types of RNA with sedimentation coefficients of 19S(20) (50) and 13S(20) (50) have been extracted from the 81S particles.