title: Polyadenylated mRNA from the photosynthetic procaryote Rhodospirillum rubrum.
abstract: Total cellular RNA extracted from Rhodospirillum rubrum cultured in butyrate-containing medium under strict photosynthetic conditions to the stationary phase of growth has been fractionated on an oligodeoxythymidylic acid-cellulose column into polyadenylated [poly(A)+] RNA and poly(A)- RNA fractions. The poly(A)+ fraction was 9 to 10% of the total bulk RNA isolated. Analysis of the poly(A)+ RNA on a denaturing urea-polyacrylamide gel revealed four sharp bands of RNA distributed in heterodisperse fashion between 16S and 9S. Similar fractionation of the poly(A)- RNA resulted in the separation of 23, 16, and 5S rRNAs and 4S tRNA. Poly(A)+ fragments isolated after combined digestion with pancreatic A and T1 RNases and analysis by denaturing gel electrophoresis demonstrated two major components of 80 and 100 residues. Alkaline hydrolysis of the nuclease-resistant, purified residues showed AMP-rich nucleotides. Through the use of snake venom phosphodiesterase, poly(A) tracts were placed at the 3' end of poly(A)+ RNA. Stimulation of [3H]leucine incorporation into hot trichloroacetic acid-precipitable polypeptides in a cell-free system from wheat germ primed by the poly(A)+ RNA mixture was found to be 220-fold higher than that for poly(A)- RNAs (on a unit mass basis), a finding which demonstrated that poly(A)+ RNAs in R. rubrum are mRNAs. Gel electrophoretic analysis of the translation mixture revealed numerous 3H-labeled products including a major band (Mr, 52,000). The parent protein was precipitated by antibodies to ribulose bisphosphate carboxylase-oxygenase and comprised 6.5% of the total translation products.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis; D001482:Base Composition; D005591:Chemical Fractionation; D011061:Poly A / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000032:analysis* / Q000302:isolation & purification; D012333:RNA, Messenger / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D012247:Rhodospirillum rubrum / Q000032:analysis* / Q000378:metabolism
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D011061:Poly A