1ij2
GCN4-pVTL Coiled-coil Trimer with Threonine at the a(16) positionGCN4-pVTL Coiled-coil Trimer with Threonine at the a(16) position
Structural highlights
FunctionGCN4_YEAST Is a transcription factor that is responsible for the activation of more than 30 genes required for amino acid or for purine biosynthesis in response to amino acid or purine starvation. Binds and recognize the DNA sequence: 5'-TGA[CG]TCA-3'. Publication Abstract from PubMedCoiled coils, estimated to constitute 3-5% of the encoded residues in most genomes, are characterized by a heptad repeat, (abcdefg)(n), where the buried a and d positions form the interface between multiple alpha-helices. Although generally hydrophobic, a substantial fraction ( approximately 20%) of these a- and d-position residues are polar or charged. We constructed variants of the well-characterized coiled coil GCN4-p1 with a single polar residue (Asn, Gln, Ser, or Thr) at either an a or a d position. The stability and oligomeric specificity of each variant were measured, and crystal structures of coiled-coil trimers with threonine or serine at either an a or a d position were determined. The structures show how single polar residues in the interface affect not only local packing, but also overall coiled-coil geometry as seen by changes in the Crick supercoil parameters and core cavity volumes. Buried polar residues in coiled-coil interfaces.,Akey DL, Malashkevich VN, Kim PS Biochemistry. 2001 May 29;40(21):6352-60. PMID:11371197[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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