Ser/Thr Protease (丝氨酸/苏氨酸蛋白酶)

Serine (Ser) proteases catalyse the hydrolysis of specific peptide bonds in their substrates and this activity depends on a set of amino acids in the active site of the enzyme, one of which is always a serine. There are two families especially well studied, the trypsin family and the subtilisin family. Serine proteases play crucial roles in a wide variety of cellular as well as extracellular functions, including the process of blood clotting, protein digestion, cell signaling, inflammation, and protein processing. Threonine (Thr) proteases are a family of proteolytic enzymes harbouring a threonine residue within the active site. The prototype members of this class of enzymes are the catalytic subunits of the proteasome, however the acyltransferases convergently evolved the same active site geometry and mechanism.