Search results
Results from the WOW.Com Content Network
DNA ligase is a type of enzyme that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond.It plays a role in repairing single-strand breaks in duplex DNA in living organisms, but some forms (such as DNA ligase IV) may specifically repair double-strand breaks (i.e. a break in both complementary strands of DNA).
The smallest known eukaryotic ligase is Chlorella virus DNA ligase (ChVLig). It contains only 298 amino acids. When ChVLig is the only source of ligase in the cell, it can continue to support mitotic development, and nonhomologous end joining in budding yeasts. [34] DNA Ligase I (Lig1) is accountable for Okazaki Fragments ligation.
DNA ligase 1 also DNA ligase I, is an enzyme that in humans is encoded by the LIG1 gene. DNA ligase 1 is the only known eukaryotic DNA ligase involved in both DNA replication and repair , making it the most studied of the ligases .
In biochemistry, a ligase is an enzyme that can catalyze the joining of two molecules by forming a new chemical bond.This is typically via hydrolysis of a small pendant chemical group on one of the molecules, typically resulting in the formation of new C-O, C-S, or C-N bonds.
Pathway preference may differ between organisms, as well. While human cells utilize both short- and long-patch BER, the yeast Saccharomyces cerevisiae was long thought to lack a short-patch pathway because it does not have homologs of several mammalian short-patch proteins, including pol β, DNA ligase III, XRCC1, and the kinase domain of PNKP.
The repair mechanisms of these sites are not fully revealed. The NHEJ is the dominant DNA repair pathway throughout the cell cycle. The DNA-PKcs protein is the critical element in the center of NHEJ. Using DNA-PKcs KO cell lines or inhibition of DNA-PKcs does not affect the repair capacity of HLS.
The resultant gap is then filled in using DNA polymerase I and DNA ligase. The basic excision process is very similar in higher cells, but these cells usually involve many more proteins – E.coli is a simple example. [5] TC-NER also exists in bacteria, and is mediated by the TRCF (Mfd) protein.
DNA ligase 3 also DNA ligase III, is an enzyme that, in humans, is encoded by the LIG3 gene. [ 5 ] [ 6 ] LIG3 encodes ATP -dependent DNA ligases that seal interruptions in the phosphodiester backbone of duplex DNA .