The GTP-Binding Domain Revisited

Abstract

Recently we explored the similarity of several GTP-binding domains using principals developed from newly reported structural features of EF-Tu (1–4). In this study, it was concluded that many GTP-binding proteins contain the following consensus sequence elements (GXXXXGK, DXXG, and NKXD) and that these elements were spaced in one of two patterns: the distance between the first and second consensus elements was either 40 to 80 amino acids or about 150 amino acids while the second and third consensus elements were usually 40 to 80 amino acids apart. An updated presentation of GTP-binding proteins which conform to this general scheme is given in Tables 1, 2, and 3 although additional sequences of the three major families have not been included (EF-Tu and EF-1a; RAS, YP2, and rho; G proteins). Each of these individual families will be the subject of more extensive study in other chapters in this book. In addition, there will be no discussion of a or s tubulin, both GTP-binding proteins, as neither of these proteins contains the three consensus elements.