Figure 1 - full size



	Figure 1 - full size

Figure 1.
FIG. 1. Structure of human p53 core domain. A, ribbon diagram of the structure of the DNA binding (core) domain in complex with consensus DNA (PDB code 1TSR [PDB] , molecule B). A -sandwich provides the basic scaffold for a loop-sheet-helix motif and two large loops tethered by a zinc ion, which interact with the major and minor groove of the DNA, respectively. The zinc ion is shown as a gray sphere, and the two DNA strands are in magenta and blue. For selected residues the side chains are shown. Among these are the six hot spot sites Arg^175, Gly^245, Arg^248, Arg^249, Arg^273, and Arg^282, which are most frequently mutated in human cancers (colored in orange). The four mutation sites in the superstable quadruple mutant M133L/V203A/N239Y/N268D (T-p53C) are highlighted as green spheres. B, close-up view of loops L2 and L3 in the DNA binding surface including the zinc coordination sphere in the structure of wild type in complex with consensus DNA (PDB code 1TSR [PDB] , molecule B). The orientation is different from the one shown for the whole molecule in A. The zinc ion is depicted as a gray sphere. Specific interactions mediated via the guanidinium group of Arg^249 are highlighted with dotted lines. These include hydrogen bonds with backbone oxygens of residues Gly^245 and Met^246 on the same loop and a salt bridge with Glu^171 on the L2 loop. DNA contacts are made via Arg^248. Selected DNA residues in the proximity of Arg^248 are shown in magenta and cyan.