conditions are described under which poly ( a ) polymerase from escherichia coli ribosomes will catalyse the addition of amp residues onto the 3'-ends of human 18 s and 28 s ribosomal rnas at an average rate of 40 amp residues per 1000 nucleotides in 20 min .
C0035553
ribosomes
C0035701
ribosomal rnas