Purification and characterization of a Saccharomyces cerevisiae exoribonuclease which yields 5'-mononucleotides by a 5'. -->. 3' mode of hydrolysis
An exoribonuclease producing 5'-mononucleotides has been purified from ribosomes of Saccharomyces cerevisiae. The enzyme has a broad pH optimum around 8.0, requires divalent cation, and is stimulated by monovalent cation with the cation and degree of stimulation being dependent on the substrate used. With either poly(a) or rRNA as substrate, the enzyme has a processive mode of hydrolysis. The oligonucleotides, (pA)/sub 3-5/, are hydrolyzed by the enzyme, and the hydrolysis is dependent on a 5'-phosphate end group. Phosphorylation of the 3' end has little effect on the rate of hydrolysis. With (/sup 3/H)poly(A) or (/sup 3/H)rRNA, labeled differentially at the 5' termini, a more rapid release of 5'-terminal label can be shown, providing evidence that the enzyme hydrolyzes in a 5' ..-->.. 3' direction. Further evidence for a 5' ..-->.. 3' mode of hydrolysis is provided by a study of the products of the hydrolysis of (/sup 3/H)(pA)/sub 5/ labeled at the 5' termini with /sup 32/P. No /sup 32/P label is found in (pA)/sub 2/ which accumulates as an intermediate.
- Research Organization:
- Oak Ridge National Lab., TN
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5308498
- Journal Information:
- J. Biol. Chem.; (United States), Vol. 255:7
- Country of Publication:
- United States
- Language:
- English
Similar Records
Exoribonuclease from Saccharomyces cerevisiae: effect of modifications of 5' end groups on the hydrolysis of substrates to 5' mononucleotides
Exoribonuclease from Saccharomyces cerevisiae: effect of modifications of 5' end groups on the hydrolysis of substrates to 5' mononucleotides
Related Subjects
RNA-ASE
BIOCHEMISTRY
PURIFICATION
BIOCHEMICAL REACTION KINETICS
HYDROLYSIS
LABELLED COMPOUNDS
MESSENGER-RNA
METABOLITES
NUCLEOTIDES
PHOSPHORUS 32
PHOSPHORYLATION
RIBOSOMES
SACCHAROMYCES CEREVISIAE
SEPARATION PROCESSES
TRITIUM
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CELL CONSTITUENTS
CHEMICAL REACTIONS
CHEMISTRY
DAYS LIVING RADIOISOTOPES
DECOMPOSITION
ENZYMES
FUNGI
HYDROGEN ISOTOPES
ISOTOPES
KINETICS
LIGHT NUCLEI
LYSIS
MICROORGANISMS
NUCLEI
NUCLEIC ACIDS
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANOIDS
PHOSPHORUS ISOTOPES
PHOSPHOTRANSFERASES
PLANTS
RADIOISOTOPES
REACTION KINETICS
RNA
SACCHAROMYCES
SOLVOLYSIS
TRANSFERASES
YEARS LIVING RADIOISOTOPES
YEASTS
550200* - Biochemistry
550700 - Microbiology