title: RNA metabolism, manganese, and RNA polymerases of zinc-sufficient and zinc-deficient Euglena gracilis.
abstract: The three major RNA classes from zinc-sufficient [(+Zn)] and zinc-deficient [(=Zn)] Euglena gracilis have been separated by affinity chromatography on oligo(dT)- and N-[N'-[m-(dihydroxyboryl)phenyl]succinamoyl]aminoethyl (DBAE)-celluloses. The total RNA content and the ribosomal and transfer RNA fractions are the same in (+Zn) and (=Zn) cells. IN (-Zn) cells, the messenger RNA fraction increases, and its altered base composition reveals additional bases and a 2-fold increase in the (G+C)/(A+U) ratio. Since the intracellular content of manganese increases in (-Zn) cells, we have examined its role in determining these changes in RNA composition. An increase in the Mn2+ content from 1 to 10 mM in assays with RNA polymerases I and II from (+Zn) cells and those with the single RNA polymerase from (-Zn) cells decreases the ratio of UMP to CMP incorporated from 1.7 to 1.0, 2.1 to 0.8 and 3.5 to 0.4, respectively. Thus, Mn2+ concentration can significantly alter the products of the enzymatic action of RNA polymerases from both (+Zn) and (-Zn) E. gracilis cells.
mesh_terms: D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D005056:Euglena gracilis / Q000378:metabolism*; D008345:Manganese / Q000378:metabolism; D012313:RNA / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D012335:RNA, Ribosomal / Q000096:biosynthesis; D012343:RNA, Transfer / Q000096:biosynthesis; D015032:Zinc / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D012335:RNA, Ribosomal; D008345:Manganese; D012313:RNA; D012343:RNA, Transfer; D012321:DNA-Directed RNA Polymerases; D015032:Zinc