Nucleotidyltransferase

Nucleotidyltransferases are transferase enzymes of phosphorus-containing groups, e.g., substituents of nucleotidylic acids or simply nucleoside monophosphates. The general reaction of transferring a nucleoside monophosphate moiety from A to B, can be written as:

A-P-N + B A + B-P-N

For example, in the case of polymerases, A is pyrophosphate and B is the nascent polynucleotide. They are classified under EC number 2.7.7 and they can be categorised into:

  1. Uridylyltransferases, which transfer uridylyl- groups
  2. Adenylyltransferases, which transfer adenylyl- groups
  3. Guanylyltransferases, which transfer guanylyl- groups
  4. Cytitidylyltransferases, which transfer cytidylyl- groups
  5. Thymidylyltransferases, which transfer thymidylyl- groups

Role in DNA repair mechanisms

Nucleotidyl transferase is a component of the repair pathway for single nucleotide base excision repair. This repair mechanism begins when a single nucleotide is recognized by DNA glycosylase as incorrectly matched or has been mutated in some way (UV light, chemical mutagen, etc.), and is removed. Later, a nucleotidyl tranferase is used to fill in the gap with the correct base, using the template strand as the reference. [1]

References

  1. ↑ Yuan Liu; Rajendra Prasad; William A. Beard; Padmini S. Kedar; Esther W. Hou; David D. Shock; Samuel H. Wilson (May 4, 2007). "Coordination of Steps in Single-nucleotide Base Excision Repair Mediated by Apurinic/Apyrimidinic Endonuclease 1 and DNA Polymerase β" (PDF). Journal of Biological Chemistry. 282 (18): 13532–13541. PMC 2366199 Freely accessible. PMID 17355977. doi:10.1074/jbc.M611295200. The enzymes and accessory factors involved in the BER subpathways in mammalian cells have received considerable attention. As summarized above, five distinct enzymatic reaction are involved during SN-BER. These are 1) removal of a modified base by a lesion-specific monofunctional DNA N-glycosylase, 2) 5'-incision of the abasic site by a hydrolytic strand incision enzyme, 3) DNA synthesis by a nucleotidyltransferase, 4) removal of the 5'-dRP group by a'-elimination reaction, and 5) nick sealing by DNA ligase (36, 37)


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