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).
Eukaryotic DNA ligase 1 catalyzes a reaction that is chemically universal to all ligases. DNA ligase 1 utilizes adenosine triphosphate (ATP) to catalyze the energetically favorable ligation events in both DNA replication and repair. During the synthesis phase (S-phase) of the eukaryotic cell cycle, DNA replication occurs.
S phase (Synthesis phase) is the phase of the cell cycle in which DNA is replicated, occurring between G 1 phase and G 2 phase. [1] Since accurate duplication of the genome is critical to successful cell division, the processes that occur during S-phase are tightly regulated and widely conserved.
The eukaryotic cell cycle consists of four distinct phases: G 1 phase, S phase (synthesis), G 2 phase (collectively known as interphase) and M phase (mitosis and cytokinesis). M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's nucleus divides, and cytokinesis, in which the cell's cytoplasm and cell membrane divides forming two daughter cells.
Cdh1 plays a pivotal role in controlling cell division at the end of mitosis and in the subsequent G1 phase of cell cycle: By recognizing and binding proteins (like mitotic cyclins) which contain a destruction box (D-box) and an additional degradation signal (KEN box), Cdh1 recruits them in a C-box-dependent mechanism to the APC for ubiquination and subsequent proteolysis.
Skp2 is the substrate recruiting component of the SCFSkp2 complex, which targets cell cycle control elements, such as p27 and p21. [28] [29] [30] Here, SKP2 has been implicated in double negative feedback loops with both p21 and p27, that control cell cycle entry and G1/S transition. [31] [32]
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.
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.