The substitutions G245C and G245D in the Zn(2+)-binding pocket of the p53 protein result in differences of conformational flexibility of the DNA-binding domain

J Biomol Struct Dyn. 2013;31(1):78-86. doi: 10.1080/07391102.2012.691364. Epub 2012 Jul 18.

Abstract

Transcription activation of the proapoptotic target genes is a means by which the p53 protein implements its function of tumor suppression. Zn(2+) is a known regulator of p53 binding to the target genes. We have previously obtained an evidence that amino acid substitutions in the p53 Zn(2+)-binding pocket can presumably exert an influence on Zn(2+) position in the Zn(2+)-p53 complex and thereby affect p53 binding to DNA. With these background considerations, our aim was to estimate the effect of the putative changes in the Zn(2+) position in its binding pocket due to the G245C and G245D substitutions on the conformation of the p53 DNA-binding motif. Statistical analysis of the molecular dynamics (MD) trajectories of the mutant p53-Zn(2+) complexes was used to detect significant deviations in conformation of the mutant p53 forms. MD simulations demonstrated that (1) the two substitutions in the Zn(2+)-binding pocket caused changes in the conformation of the p53 DNA-binding motif, as compared with the wild-type (WT) p53; (2) binding of Zn(2+) to the p53 mutant forms reduced the effect of the substitutions on conformational change; and (3) Zn(2+) binding in the normal position compensated the effect of the mutations on the conformation in comparison to the altered Zn(2+) position.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Binding Sites
  • Carrier Proteins / chemistry*
  • Carrier Proteins / pharmacology
  • DNA / chemistry*
  • DNA / metabolism
  • Molecular Dynamics Simulation
  • Mutation
  • Protein Conformation
  • Tumor Suppressor Protein p53 / chemistry*
  • Tumor Suppressor Protein p53 / metabolism
  • Zinc / chemistry*
  • Zinc / metabolism

Substances

  • Carrier Proteins
  • Tumor Suppressor Protein p53
  • zinc-binding protein
  • DNA
  • Zinc