Association of higher molecular weight ribonucleoproteins of 7 S particle preparations with multimers of transcription factor IIIA.
High molecular weight (HMW) fractions of Xenopus laevis 7 S ribonucleoprotein (RNP) particle preparations were analyzed for RNA and protein content. RNA/protein ratios, amino acid analyses and Western blots reveal that the major HMW fraction from a non-denaturing polyacrylamide gel (band b) contains two molecules of transcription factor protein IIIA (TFIIIA) to one 5 S RNA. Another HMW band appears to contain 4 molecules of TFIIIA to one 5 S RNA. Yet another RNP band (band a) contains 5 S RNA and a protein unrelated to TFIIIA. Thus, native 7 S particle preparations contain 5 S RNA bound to multimeric forms of TFIIIA as well as to an unrelated protein. The presence of additional TFIIIA molecules associated with 7 S particles may have significance in the sequestering of TFIIIA during transcriptional regulation of the 5 S gene.
Coyer
J
J
Department of Microbiology, State University of New York, Stony Brook 11794.
Andersen
J
J
Delihas
N
N
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D008970:Molecular Weight; D009865:Oocytes / Q000032:analysis; D012335:RNA, Ribosomal / Q000302:isolation & purification*; D012341:RNA, Ribosomal, 5S / Q000302:isolation & purification*; D012261:Ribonucleoproteins / Q000302:isolation & purification*; D035582:Transcription Factor TFIIIA; D014157:Transcription Factors / Q000302:isolation & purification*; D014982:Xenopus laevis
D000596:Amino Acids; D012335:RNA, Ribosomal; D012341:RNA, Ribosomal, 5S; D012261:Ribonucleoproteins; D035582:Transcription Factor TFIIIA; D014157:Transcription Factors