Rawlings N D, Barrett A J
Strangeways Research Laboratory, Cambridge, United Kingdom.
Methods Enzymol. 1994;244:19-61. doi: 10.1016/0076-6879(94)44004-2.
This chapter examines families of serine peptidases. Serine peptidases are found in viruses, bacteria, and eukaryotes. They include exopeptidases, endopeptidases, oligopeptidases, and omega peptidases. On the basis of three-dimensional structures, most of the serine peptidase families can be grouped together into about six clans that may have common ancestors. The structures are known for members of four of the clans, chymotrypsin, subtilisin, carboxypeptidase C, and D-Ala-D-Ala peptidase A. The peptidases of chymotrypsin, subtilisin, and carboxypeptidase C clans have a common “catalytic triad” of three amino acids—namely, serine (nucleophile), aspartate (electrophile), and histidine (base). The geometric orientations of these are closely similar between families; however the protein folds are quite different. The arrangements of the catalytic residues in the linear sequences of members of the various families commonly reflect their relationships at the clan level. The members of the chymotrypsin family are almost entirely confined to animals. 10 families are included in chymotrypsin clan (SA), and all the active members of these families are endopeptidases. The order of catalytic residues in the polypeptide chain in clan SA is His/Asp/Ser.
本章探讨丝氨酸蛋白酶家族。丝氨酸蛋白酶存在于病毒、细菌和真核生物中。它们包括外肽酶、内肽酶、寡肽酶和ω肽酶。基于三维结构，大多数丝氨酸蛋白酶家族可归为约六个可能有共同祖先的家族。其中四个家族（胰凝乳蛋白酶、枯草杆菌蛋白酶、羧肽酶C和D - 丙氨酰 - D - 丙氨酸肽酶A）成员的结构是已知的。胰凝乳蛋白酶、枯草杆菌蛋白酶和羧肽酶C家族的蛋白酶具有由三个氨基酸组成的共同“催化三联体”，即丝氨酸（亲核试剂）、天冬氨酸（亲电试剂）和组氨酸（碱）。这些氨基酸在各家族之间的几何取向非常相似；然而蛋白质折叠却大不相同。各家族成员线性序列中催化残基的排列通常反映了它们在家族水平上的关系。胰凝乳蛋白酶家族的成员几乎完全局限于动物。胰凝乳蛋白酶家族（SA）包括10个家族，这些家族的所有活性成员都是内肽酶。SA家族中多肽链上催化残基的顺序是His/Asp/Ser。
