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Mammalian DNA ligases
Author(s) -
Tomkinson Alan E.,
Levin David S.
Publication year - 1997
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.950191009
Subject(s) - dna ligase , biology , dna repair , dna polymerase mu , xrcc1 , dna clamp , in vitro recombination , ubiquitin ligase , dna ligases , microbiology and biotechnology , dna polymerase ii , dna polymerase , dna , genetics , gene , ubiquitin , circular bacterial chromosome , complementary dna , molecular cloning , polymerase chain reaction , reverse transcriptase , genotype , single nucleotide polymorphism
Abstract DNA joining enzymes play an essential role in the maintenance of genomic integrity and stability. Three mammalian genes encoding DNA ligases, LIG1, LIG3 and LIG4 , have been identified. Since DNA ligase II appears to be derived from DNA ligase III by a proteolytic mechanism, the three LIG genes can account for the four biochemically distinct DNA ligase activities, DNA ligases I, II, III and IV, that have been purified from mammalian cell extracts. It is probable that the specific cellular roles of these enzymes are determined by the proteins with which they interact. The specific involvement of DNA ligase I in DNA replication is mediated by the non‐catalytic amino‐terminal domain of this enzyme. Furthermore, DNA ligase I participates in DNA base excision repair as a component of a multiprotein complex. Two forms of DNA ligase III are produced by an alternative splicing mechanism. The ubiqitously expressed DNA ligase III‐α forms a complex with the DNA single‐strand break repair protein XRCC1. In contrast, DNA ligase III‐β, which does not interact with XRCC1, is only expressed in male meiotic germ cells, suggesting a role for this isoform in meiotic recombination. At present, there is very little information about the cellular functions of DNA ligase IV.