title: 5' Caps in hnRNA: absence of m32,2,7G and size distribution of capped molecules.
abstract: In HeLa cells the "small nuclear" RNA has a cap II 5' structure (8)-- m32,2,7G(5') pppXmpYmp-- where X and Y are 2'0 methylated adenosine and uridine. In contrast hnRNA contains only cap I structures were the 2'0 methylated residue may be any base as was earlier reported for cytoplasmic mRNA (8,9,11). With a clear distinction between the source of these two caps an analysis of the size distribution of capped hnRNA could be performed which revealed over 65% of the capped hnRNA molecules were larger than cytoplasmic mRNA.
mesh_terms: D002467:Cell Nucleus / Q000032:analysis; D006151:Guanosine / Q000032:analysis*; D006367:HeLa Cells / Q000032:analysis; D009843:Oligoribonucleotides / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm; D012260:Ribonucleases; D012265:Ribonucleotides / Q000032:analysis
chemical_list: D009843:Oligoribonucleotides; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D012265:Ribonucleotides; D006151:Guanosine; D012260:Ribonucleases