EC Number   |
Substrates |
Organism |
Products  |
Reversibility |
|---|
   2.7.7.72 | more |
NTSFIII is inactive with CTP and tRNAAsp-C as substrates |
Geobacter sulfurreducens |
? |
- |
? |
| 2.7.7.72 | more |
the CCA-adding enzymes can use three different substrates: tRNAs lacking one, i.e. tRNA-CC, two, i.e. tRNA-C, or all three 3'-terminal nucleotides, tRNA. The CCA-adding enzyme recognizes primarily the top half tRNA minihelix |
Escherichia coli |
? |
- |
? |
| 2.7.7.72 | more |
the CCA-adding enzymes can use three different substrates: tRNAs lacking one, i.e. tRNA-CC, two, i.e. tRNA-C, or all three 3'-terminal nucleotides, tRNA. The Sulfolobus shibatae CCA-adding enzyme forms a stable complex with tRNA. The CCA-adding enzyme recognizes primarily the top half tRNA minihelix |
Saccharolobus shibatae |
? |
- |
? |
| 2.7.7.72 | more |
the enzyme catalyses a unique template-independent but sequence-specific nucleotide polymerization reaction, active site structure and molecular mechanism, overview. Construction of a corkscrew model for CCA addition that includes a fixed active site and a traveling tRNA-binding region formed by flexible parts of the protein |
Homo sapiens |
? |
- |
? |
| 2.7.7.72 | more |
the HD domain of the enzyme also exhibits 2',3'-cyclic phosphodiesterase, 2'-nucleotidase, and Ni2+-dependent phosphatase activities, overview |
Escherichia coli |
? |
- |
? |
| 2.7.7.72 | more |
the tRNA substrate must remain fixed on the enzyme surface during CA addition, tRNA-C cross-linked to the enzyme remains fully active for addition of CTP and ATP. The growing 3'-terminus of the tRNA progressively refolds to allow the solitary active site to reuse a single CTP binding site. The ATP binding site is then created collaboratively by the refolded CCterminus and the enzyme, and nucleotide addition ceases when the nucleotide binding pocket is full. The template for CCA addition is a dynamic ribonucleoprotein structure. Both CTP addition to tRNA-C and ATP addition to tRNA-CC are dramatically inhibited by alkylation of the same tRNA phosphates in the acceptor stem and TPsiC stem-loop |
Saccharolobus shibatae |
? |
- |
? |
| 2.7.7.72 | more |
the tRNA substrate must remain fixed on the enzyme surface during CA addition. Both CTP addition to tRNA-C and ATP addition to tRNA-CC are dramatically inhibited by alkylation of the same tRNA phosphates in the acceptor stem and TPsiC stem-loop |
Escherichia coli |
? |
- |
? |
| 2.7.7.72 | more |
CCA-adding enzymes recognize tRNA and tRNA-like structures as substrates, select and discriminate the correct nucleotides CTP and ATP against UTP and GTP, and, after incorporation of two C residues, the nucleotide specificity has to switch towards ATP without the help of a nucleic acid template. The enzymes have to stop polymerization exactly after three positions and recognize partial CCA-ends and add only the missing residues for completion, instead of stubbornly adding CCA-ends to their substrates, overview |
Thermus thermophilus |
? |
- |
? |
| 2.7.7.72 | more |
CCA-adding enzymes recognize tRNA and tRNA-like structures as substrates, select and discriminate the correct nucleotides CTP and ATP against UTP and GTP, and, after incorporation of two C residues, the nucleotide specificity has to switch towards ATP without the help of a nucleic acid template. The enzymes have to stop polymerization exactly after three positions and recognize partial CCA-ends and add only the missing residues for completion, instead of stubbornly adding CCA-ends to their substrates, overview |
Escherichia coli |
? |
- |
? |
| 2.7.7.72 | more |
CCA-adding enzymes recognize tRNA and tRNA-like structures as substrates, select and discriminate the correct nucleotides CTP and ATP against UTP and GTP, and, after incorporation of two C residues, the nucleotide specificity has to switch towards ATP without the help of a nucleic acid template. The enzymes have to stop polymerization exactly after three positions and recognize partial CCA-ends and add only the missing residues for completion, instead of stubbornly adding CCA-ends to their substrates, overview |
Homo sapiens |
? |
- |
? |
