title: tRNA splicing in yeast and wheat germ. A cyclic phosphodiesterase implicated in the metabolism of ADP-ribose 1",2"-cyclic phosphate.
abstract: Adenosine diphosphate (ADP)-ribose 1",2"-cyclic phosphate (Appr > p) is produced as a result of transfer RNA (tRNA) splicing in the yeast Saccharomyces cerevisiae and probably in other eukaryotes. Endonucleolytic cleavage and ligation result in a mature length tRNA with a 2'-phosphate at the splice junction. This 2'-phosphate is transferred to NAD to produce Appr > p. Metabolism of Appr > p requires hydrolysis of the 1",2"-cyclic phosphate linkage. We show here that yeast has a unique cyclic phosphodiesterase that can hydrolyze Appr > p, ribose 1,2-cyclic phosphate, and ribose 1,3-cyclic phosphate to the corresponding ribose 1-phosphate derivatives. The cyclic phosphodiesterase is highly specific for Appr > p; there is 20-fold less activity on ribose 1,3-cyclic phosphate and no detectable activity on nucleoside 2',3'-cyclic phosphates. A similar cyclic phosphodiesterase is present in wheat germ. The wheat germ cyclic phosphodiesterase activity co-chromatographs with a 2',3'-cyclic nucleotide 3'-phosphodiesterase that was previously identified and purified. The purified wheat germ enzyme has a distinct preference for Appr > p and ribose cyclic phosphate compared to guanosine 2',3'-cyclic phosphate and shares other biochemical characteristics with the yeast enzyme.
authors.affiliation: Department of Biochemistry, University of Rochester, School of Medicine and Dentistry, New York 14642.
authors.forename: G M
authors.initials: GM
authors.lastname: Culver
authors.forename: S A
authors.initials: SA
authors.lastname: Consaul
authors.forename: K T
authors.initials: KT
authors.lastname: Tycowski
authors.forename: W
authors.initials: W
authors.lastname: Filipowicz
authors.forename: E M
authors.initials: EM
authors.lastname: Phizicky
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000502:physiology*; D012326:RNA Splicing; D012343:RNA, Transfer / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014908:Triticum / Q000235:genetics
chemical_list: D010710:Phosphates; D000246:Adenosine Diphosphate Ribose; D012343:RNA, Transfer; D010727:Phosphoric Diester Hydrolases