Methylated bases and sugars in 16-S and 28-S RNA from L cells

Abstract

1. Sugar-methylated and base-methylated compounds in alkali hydrolysates of L cell 16-S and 28-S RNA have been examined. 2. The extent of sugar methylation is much greater than the degree of base methylation in both 16-S and 28-S RNA. 3. The sugar-methylated nucleotides ( O 2′- methyladenylate , O 2′- methylguanylate , O 2′- methylcytidylate , O 2′- methyluridylate ) are present in both 16-S and 28-S RNA. 4. Most of the sixteen possible alkali-stable sequences of the type NmpN, in which Nm is an O 2′- methylated derivative of one of the four major nucleosides, have been recovered as dinucleoside phosphates from both 16-S and 28-S RNA. 5. The base-methylated nucleotides ( N 6- methyladenylate , N 6- dimethyladenylate ) are present in 16-S RNA, and the base-methylated nucleotides ( N 6- methyladenylate , 5-methylcytidylate) are present in 28-S RNA. 6. The analytical data have been evaluated and discussed in terms of the possibility that polynucleotides in 16-S RNA are heterogeneous, and also in terms of the possibility that 16-S polynucleotides may be involved in intracellular protein synthesis.