Intrinsic differences in backbone dynamics between wild type and DNA-contact mutants of p53 DNA binding domain revealed by NMR spectroscopy.
 

Intrinsic differences in backbone dynamics between wild type and DNA-contact mutants of p53 DNA binding domain revealed by NMR spectroscopy.

Intrinsic differences in backbone dynamics between wild type and DNA-contact mutants of p53 DNA binding domain revealed by NMR spectroscopy.

Biochemistry. 2017 Aug 24;:

Authors: Rasquinha JA, Bej A, Dutta S, Mukherjee S

Abstract
Mutations in p53's DNA binding domain (p53DBD) are associated with 50% of all cancers, making it an essential system to investigate in order to understand the genesis and progression of cancer. In this work, we studied the changes in structure and dynamics of wild type p53DBD in comparison with two of its "hotspot" DNA contact mutants, R248Q and R273H, by analysis of backbone amide chemical shift perturbations and 15N spin relaxation measurements. The results of amide chemical shift changes indicated significantly more perturbations in the R273H mutant in comparison to the wild type and R248Q p53DBD. Analysis of 15N spin relaxation rates and the resulting NMR order parameters suggest that for most parts, the R248Q mutant exhibits limited conformational flexibility and is similar to the wild type protein. In contrast, R273H showed significant backbone dynamics extending up to its ?-sandwich scaffold in addition to motions along the DNA binding interface. Furthermore, comparison of rotational correlation times between the mutants suggest that R273H mutant, with a higher correlation time, forms an enlarged structural fold in comparison to the R248Q mutant and wild type p53DBD. Finally, we identify three regions in these proteins that show conformational flexibility to varying degrees, which suggests that R273H mutant, in addition to being a DNA-contact mutation, exhibits properties of a conformational mutant as well.


PMID: 28836764 [PubMed - as supplied by publisher]



More...