Sandbox 201: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 10: | Line 10: | ||
Rnl1 is in fact a tRNA repair enzyme used by the T4 bacteriophage to escape hosts antiviral response. Enzyme functioning requires ATP and divalent metal ions. The T4 ligase repairs the tRNA<sup>Lys</sup> by joining its 5'-PO<sub>4</sub> and 3'-OH groups via series of three nucleotidyl transfer steps in a ping-pong enzymatic mechanism. First, the Lys<sup>99</sup> of the enzyme reacts with the a phosphorus of ATP and forms a covalent intermediate: ligase-(lysyl-N)-AMP. Pyrophosphate is also produced during this step. Secondly, AMP is transferred from the intermediate to the 5'- PO<sub>4</sub> terminus of a tRNA to form an tRNA-adenylate intermediate (AppRNA). Finally, the ligase catalyzes the attack of the 3'-OH terminus of the tRNA on the tRNA-adenylate and the two termini are joined via a phosphodiester bond, the AMP is released. | Rnl1 is in fact a tRNA repair enzyme used by the T4 bacteriophage to escape hosts antiviral response. Enzyme functioning requires ATP and divalent metal ions. The T4 ligase repairs the tRNA<sup>Lys</sup> by joining its 5'-PO<sub>4</sub> and 3'-OH groups via series of three nucleotidyl transfer steps in a ping-pong enzymatic mechanism. First, the Lys<sup>99</sup> of the enzyme reacts with the a phosphorus of ATP and forms a covalent intermediate: ligase-(lysyl-N)-AMP. Pyrophosphate is also produced during this step. Secondly, AMP is transferred from the intermediate to the 5'- PO<sub>4</sub> terminus of a tRNA to form an tRNA-adenylate intermediate (AppRNA). Finally, the ligase catalyzes the attack of the 3'-OH terminus of the tRNA on the tRNA-adenylate and the two termini are joined via a phosphodiester bond, the AMP is released. | ||
<br/><br/> | |||
==Biological role== | ==Biological role== | ||
