Crystallographic analysis reveals that anticancer clinical candidate L-778,123 inhibits protein farnesyltransferase and geranylgeranyltransferase-I by different binding modes.

Journal Article

Many signal transduction proteins that control growth, differentiation, and transformation, including Ras GTPase family members, require the covalent attachment of a lipid group by protein farnesyltransferase (FTase) or protein geranylgeranyltransferase type-I (GGTase-I) for proper function and for the transforming activity of oncogenic mutants. FTase inhibitors are a new class of potential cancer therapeutics under evaluation in human clinical trials. Here, we present crystal structures of the clinical candidate L-778,123 complexed with mammalian FTase and complexed with the related GGTase-I enzyme. Although FTase and GGTase-I have very similar active sites, L-778,123 adopts different binding modes in the two enzymes; in FTase, L-778,123 is competitive with the protein substrate, whereas in GGTase-I, L-778,123 is competitive with the lipid substrate and inhibitor binding is synergized by tetrahedral anions. A comparison of these complexes reveals that small differences in protein structure can dramatically affect inhibitor binding and selectivity. These structures should facilitate the design of more specific inhibitors toward FTase or GGTase-I. Finally, the binding of a drug and anion together could be applicable for developing new classes of inhibitors.

Full Text

Duke Authors

Cited Authors

  • Reid, TS; Long, SB; Beese, LS

Published Date

  • July 20, 2004

Published In

Volume / Issue

  • 43 / 28

Start / End Page

  • 9000 - 9008

PubMed ID

  • 15248757

Pubmed Central ID

  • 15248757

International Standard Serial Number (ISSN)

  • 0006-2960

Digital Object Identifier (DOI)

  • 10.1021/bi049280b


  • eng

Conference Location

  • United States