| Autor: |
Gross, Hans J., Duerinck, Fred R., Fiers, Walter C. |
| Předmět: |
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| Zdroj: |
European Journal of Biochemistry; 1970, Vol. 17 Issue 1, p116-123, 8p |
| Abstrakt: |
tRNA pyrophosphorylase was partially purified from Escherichia coli MRE 600 cells. Upon chromatography on a DEAE-cellulose column, two enzymatic activity peaks were partially resolved. Gel filtration indicated a molecular weight of approx. 42000 dalton for both. Some general properties are reported. The only consistent difference between the two enzyme fractions was that the first incorporated more AMP-residues for a given tRNA preparation, as if the second has a more restricted specificity with respect to the acceptor tRNA molecules in the adenylation reaction. Partial degradation of tRNA by combined digestion with ribonaclease T1 and spleen exonuclease indicated a rapid removal of approx. 16 nucleotides per tRNA molecule, presumably from more exposed regions. The amino acid aceptor activity was more sensitive to this nuclease pretreatment than the 3'-terminal adenylic acid acceptor activity. Direct analysis showed that RNA fragments of chain length approx. 40 and even 10 were still functional in accepting terminal adenylic acid. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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