Repair Mechanisms
Maintaining the integrity of its genetic blueprint is of central importance for a living cell and the organism of which it is a part. To preserve the function of the genetic material within the cell and to ensure its accurate transmission to future generations, numerous mechanisms have evolved to repair errors and damage in DNA. As an example of the cellular resources devoted to this end, consider that of 1709 proteins encoded by the first bacterial genome to be sequenced, that of Haemophilus influenzae, at least 45 function in DNA repair mechanisms. The complementary, double-stranded structure of DNA, a crucial feature that allows it to be readily replicated, also facilitates its repair. The objects of repair range from mismatched bases resulting from errors in DNA replication to base damage and even gross distortion of the DNA structure by physical and chemical agents. In a few instances damage is directly reversed. Most repair mechanisms, however, first remove the damaged region together with a segment of the DNA strand in which it occurred and then resynthesize that segment correctly using the complementary strand as a template. Depending on the component initially removed or recognized, these mechanisms have been categorized as base excision, nucleotide (oroligonucleotide) excision, and mismatch repair. When the damage cannot be so simply repaired, a mechanism of recombinational repair, requiring interaction with another copy of the genome, may intervene.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research (ER) (US)
- DOE Contract Number:
- AC02-98CH10886
- OSTI ID:
- 770788
- Report Number(s):
- BNL-66655; R&D Project: BO-73; KP110201; TRN: US200509%%219
- Resource Relation:
- Other Information: PBD: 9 Jul 1999
- Country of Publication:
- United States
- Language:
- English
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