Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Co2+ | enzyme requires a divalent cation for activity. This requirement can be satisfied by Mg2+, Mn2+ or Co2+ | Escherichia coli | |
Mg2+ | enzyme requires a divalent cation for activity. This requirement can be satisfied by Mg2+, Mn2+ or Co2+ | Escherichia coli | |
Mn2+ | enzyme requires a divalent cation for activity. This requirement can be satisfied by Mg2+, Mn2+ or Co2+ | Escherichia coli |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
- |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | alteration of the 3'-terminal base has no effect on the rate of hydrolysis, whereas modification of the 3'-terminal sugar has a major effect. tRNA terminating with a 3'-phosphate is completely inactive as a substrate. The rate of hydrolysis of intact tRNA is very slow compared to tRNAs containing extra residues or compared to tRNAs from which part of the -C-C-A sequence has been removed. Oxidation of the terminal sugar, reduction of the dialdehyde with borohydride, or removal of the terminal AMP from intact tRNA increase the activity of the substrate. Addition of a second -C-C-A sequence gives an active substrate indicating that the relative resistance of intact tRNA to RNase D hydrolysis is not due to the sequence per se but to the structural environment of the 3'-terminus. The enzyme is an exonuclease which initiates hydrolysis at the 3'-terminus and removes 5'-mononucleotides in a random fashion | Escherichia coli | ? | - |
? | |
tRNA-C-C-A-Cn + H2O | - |
Escherichia coli | tRNA-C-C-A-Cn-1 + cytosine | - |
? |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
9.1 | 9.5 | - |
Escherichia coli |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
8 | 10.3 | pH 8.0: about 50% of maximal activity, pH 10.3: about 70% of maximal activity | Escherichia coli |