Biology:LigD

From HandWiki
Multifunctional non-homologous end joining protein LigD
Identifiers
OrganismMycolicibacterium smegmatis ATCC 700084
SymbolligD
UniProtA0R3R7

LigD is a multifunctional ligase/polymerase/nuclease (3'-phosphoesterase) found in bacterial non-homologous end joining (NHEJ) DNA repair systems.[1] It is much more error-prone than the more complex eukaryotic system of NHEJ, which uses multiple enzymes to fill its role.[2] The polymerase preferentially use rNTPs (RNA nucleotides), possibly advantageous in dormant cells.[3]

The actual architecture of LigD is variable.

  • The LigD homolog in Bacillus subtilis does not have the nuclease domain.
  • LigD with its ligase domain artificially removed can perform its function (with loss of fidelity) with a separate LigC acting as the ligase.[2]
  • The LigD homolog in the archaeon Methanocella paludicola is broken into three single-domain proteins sharing an operon.[4]

References

  1. "Mycobacterial Ku and ligase proteins constitute a two-component NHEJ repair machine". Science 306 (5696): 683–5. October 2004. doi:10.1126/science.1099824. PMID 15499016. Bibcode2004Sci...306..683D. 
  2. 2.0 2.1 "Mechanism of nonhomologous end-joining in mycobacteria: a low-fidelity repair system driven by Ku, ligase D and ligase C". Nat. Struct. Mol. Biol. 12 (4): 304–12. April 2005. doi:10.1038/nsmb915. PMID 15778718. 
  3. "NHEJ protects mycobacteria in stationary phase against the harmful effects of desiccation". DNA Repair (Amst.) 6 (9): 1271–6. September 2007. doi:10.1016/j.dnarep.2007.02.009. PMID 17360246. http://sro.sussex.ac.uk/1122/1/DNA_Doherty.pdf. 
  4. Bartlett, EJ; Brissett, NC; Doherty, AJ (28 May 2013). "Ribonucleolytic resection is required for repair of strand displaced nonhomologous end-joining intermediates.". Proceedings of the National Academy of Sciences of the United States of America 110 (22): E1984-91. doi:10.1073/pnas.1302616110. PMID 23671117. Bibcode2013PNAS..110E1984B.