title: [B2 RNA and 7SK RNA, transcripts of RNA-polymerase III, have a cap-like structure at the 5'-end].
abstract: We found that hydrolysates of poly(A)RNA from Ehrlich ascites carcinoma cells which were transcribed by RNA polymerase III contained an unusual component designated as X. It was part of B2 RNA representing a transcript of B2 retroposon, typical of rodents. The component X possesses a cap-like structure, xPPP5'G, where x has al non-nucleotide structure. About half of all B2 RNAs contained this group at the 5'-end. Previously, Epstein et al. (Epstein P., Reddy R., Henning D., Busch H. parallel J. Biol. Chem. 1980. V. 255. P. 8901-8906) detected a similar structure at the 5'-end of small nuclear U6RNA. Later, Singh and Reddy (Singh R., Reddy R. parallel Proc. Natl. Acad. Sci. USA. 1989. V. 86. P. 8280-8283) showed methyl to be the blocking group in the component X of U6RNA. Besides B2 RNA, we found 5'-ends containing methyl groups in 7S K-RNA.
authors.forename: G P
authors.initials: GP
authors.lastname: Shumiatskiĭ
authors.forename: S V
authors.initials: SV
authors.lastname: Tillib
authors.forename: D A
authors.initials: DA
authors.lastname: Dramerov
mesh_terms: D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000737:chemistry / Q000235:genetics; D002855:Chromatography, Thin Layer; D004591:Electrophoresis, Polyacrylamide Gel; D051379:Mice; D009690:Nucleic Acid Conformation; D011061:Poly A / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*; D012320:RNA Polymerase III / Q000737:chemistry*; D012333:RNA, Messenger; D012261:Ribonucleoproteins / Q000737:chemistry*; D017411:Ribonucleoproteins, Small Nuclear; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; D011061:Poly A; D012313:RNA; D012320:RNA Polymerase III
vernacular_title: B2-RNK i 7SK-RNK, transkripty RNK-polimerazy III, imeiut na 5'-kontse kep-podobnuiu strukturu.