Farmer 2 gal4sandbox: Difference between revisions

A specific DNA complex of the 65-residue, N-terminal fragment of the yeast transcriptional activator, GAL4, has been analysed at 2.7 A resolution by X-ray crystallography. The protein binds as a <scene name='71/711060/Dimer/1'>dimer</scene> to a symmetrical 17-base-pair sequence. Each subunit folds into 3 distinct modules: A compact, <scene name='71/711060/Metal_binding_domain/1'>metal binding domain</scene>, and an <scene name='71/711060/Extended_linker/1'>extended linker</scene> (41-49), and an <scene name='71/711060/Dimerization_element/1'>alpha-helical dimerization element</scene> (50-64). A small, Zn(2+)-containing domain recognizes a conserved CCG triplet at each end of the site through direct contacts with the major groove. A short coiled-coil dimerization element imposes 2-fold symmetry. A segment of extended polypeptide chain links the metal-binding module to the dimerization element and specifies the length of the site. The relatively open structure of the complex would allow another protein to bind coordinately with GAL4.