Purification of RNA 3'-terminal phosphate cyclase from HeLa cells. Covalent modification of the enzyme with different nucleotides.
- Vicente O Friedrich Miescher-Institut, Basel, Switzerland.
- Filipowicz W
- 1988-09-15
Published in:
- European journal of biochemistry. - 1988
Adenosine Triphosphate
Centrifugation, Density Gradient
Chromatography
Cytidine Triphosphate
Electrophoresis, Polyacrylamide Gel
Enzyme Activation
Guanosine Triphosphate
HeLa Cells
Humans
Hydrogen-Ion Concentration
Ligases
Nucleotides
Uridine Triphosphate
English
RNA 3'-terminal phosphate cyclase has been purified about 6000-fold to near homogeneity from HeLa cells. The purified protein is a single polypeptide with an Mr of 38,000-40,000 and a Stokes radius of 2.66 nm. The cyclase shows a pH optimum of 8.0-9.0. In the presence of Mg2+ and ATP this enzyme catalyzes the conversion of a 3'-phosphate group into the cyclic 2',3'-phosphodiester at the 3' end of RNA, through formation of a covalent cyclase-AMP intermediate. GTP, CTP and UTP (but not dATP or ADP) can also function as cofactors in the cyclization reaction, although less efficiently (apparent Km values for ATP and GTP are 6 microM and 200 microM, respectively). Consistent with this, the enzyme can be covalently labelled with the four [alpha-32P]NTPs.
- Language
-
- English
- Open access status
- bronze
- Identifiers
-
- DOI 10.1111/j.1432-1033.1988.tb14300.x
- PMID 3416880
- Persistent URL
- https://susi.usi.ch/global/documents/216705
Statistics
Document views: 8
File downloads:
- fulltext.pdf: 0