| Autor: |
Spacciapoli, P, Doviken, L, Mulero, J J, Thurlow, D L |
| Zdroj: |
Journal of Biological Chemistry; March 1989, Vol. 264 Issue: 7 p3799-3805, 7p |
| Abstrakt: |
Treatment of tRNA with diethyl pyrocarbonate or hydrazine prior to incubation with the enzyme ATP/CTP:tRNA nucleotidyltransferase and [α-32P]ATP results in exclusion of modified bases from labeled molecules. Purines modified with diethyl pyrocarbonate, which interfere with enzyme recognition, cluster at the corner of the tRNA molecule, where the D- and psi-loops are juxtaposed in all 15 tRNAs used in this study. When the enzyme is isolated from Escherichia coli, few other sites of interference are evident near the 3′-end; when the homologous enzyme from yeast is used, more exclusions are apparent near the 3′-end. Modification of uridines with hydrazine has no effect on interaction with the enzyme, except for one uridine near the 3′-end of tRNAGly. Interference of enzyme activity by modified bases can be overcome by longer incubation times or increased concentrations of enzyme. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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