A model for the tertiary structure of p21, the product of the ras oncogene.
A model was developed for the structure of p21, the protein with a molecular weight of 21,000 that is produced by the ras genes. This model predicts that p21 consists of a central core of beta-sheet structure, connected by loops and alpha helices. Four of these loops comprise the guanine nucleotide binding site. The phosphoryl binding region is made up of amino acid sequences from 10 to 16 and from 57 to 63 of p21. The latter sequence may contain a site for magnesium binding. Amino acids defining guanine specificity are Asn-116 and Asp-119, and sequences around amino acid 145 may contribute to guanine binding. The model makes it possible to visualize how oncogenic mutations of p21 affect interaction with guanine nucleotides.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001221:Aspartate Carbamoyltransferase; D001483:Base Sequence; D001665:Binding Sites; D002223:Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing); D002417:Cattle; D004080:Dihydroorotase; D004926:Escherichia coli; D006150:Guanine Nucleotides / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances; D008274:Magnesium / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis; D008956:Models, Chemical; D009097:Multienzyme Complexes; D009154:Mutation; D009857:Oncogenes; D010444:Peptide Elongation Factor Tu; D010445:Peptide Elongation Factors / Q000032:analysis; D011487:Protein Conformation; D011506:Proteins / Q000032:analysis*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D015293:Transducin
D000596:Amino Acids; C033626:CAD trifunctional enzyme; D006150:Guanine Nucleotides; D046911:Macromolecular Substances; D008565:Membrane Proteins; D009097:Multienzyme Complexes; D010445:Peptide Elongation Factors; D011506:Proteins; D012346:RNA, Transfer, Amino Acyl; D001221:Aspartate Carbamoyltransferase; D004080:Dihydroorotase; D010444:Peptide Elongation Factor Tu; D015293:Transducin; D002223:Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing); D008274:Magnesium