Ligase

Part of speech: noun

Pronunciation: /ˈlɪɡeɪz/

Definitions

1. An enzyme that aids in the synthesis and repair of nucleic acids by facilitating the covalent bonding of large molecular structures together
2. This type of enzyme promotes the joining of various biological molecules by creating new chemical bonds, essential for nucleic acid integrity
3. A catalyst that facilitates the connection of two molecules by forming a chemical bond, especially in DNA or RNA synthesis

Etymology: Ligase is a straightforward coinage from biochemistry. It combines "ligation", the process of tying or binding something together, with the suffix "-ase", which chemists attach to the names of enzymes. The "-ase" ending was standardised in the nineteenth century, when the French chemist Anselme Payen isolated the first enzyme, diastase, from barley malt, and later enzymes were named by adding "-ase" to the name of the substance they acted upon or the reaction they catalysed. Ligation itself comes from the Latin "ligare", meaning "to bind" or "to tie", which also gave English "ligament" and "obligation". Ligase therefore names an enzyme whose job is to bind, or join, two molecular pieces together. The term describes a specific function: in DNA replication and repair, ligases seal the gaps in the sugar-phosphate backbone, joining the ends of separate strands into a continuous chain.