DNA-Ligase

• CAS Number: 9015-85-4
• CAS Number: 37259-52-2

DNA ligases are enzymes link the DNA strands. You case form an ester bond between a phosphate group and the sugar deoxyribose. You belong in the EC numbers nomenclature to the ligases and possess the number EC 6.5.1. -.

Slashed nucleic acids generated by various processes within cells:

• In DNA replication built on the discontinuous string non-contiguous pieces of DNA, the Okazaki fragments. The combination of these pieces is accomplished by ligases.
• At different DNA repair mechanisms to repair the strand breaks ligases.
• Occurs during the splicing strand breaks by ligases be closed again.

Use

The molecular biology of organisms isolated or recombinant ligases are an indispensable tool, eg for genetic engineering: To selectively re- connect the DNA fragments together, the sliced ​​by restriction endonucleases fragments together with DNA ligase and the corresponding cofactor incubated. The ligase, the DNA strands, so that, for example, again resulting in a circular plasmid, which can then be transformed into bacterial cells.

DNA ligase most often used are:

• T4 DNA ligase: It can connect both smooth and overhanging restriction ends. As a cofactor, this enzyme requires ATP.
• E. coli DNA ligase: You can not associate any smooth ends and needs overhanging ends. As a cofactor NAD requires this enzyme.