stoichiometric measurements , performed by densitometric scanning on ribosomal proteins extracted from high-salt dissociated subunits revealed that isolated ribosomal subunits contain , besides some protein species occurring in submolar amounts , a number of protein species which are present in multiple copies : s13 , s27 , l22 , l31 , l33 , l34 and l39 .
C0035552
ribosomal proteins
C0033684
protein