Download MendeleyA Mutation Directs the Structural Switch of DNA Binding Proteins under Starvation to a Ferritin-like Protein Cage.
Williams, S.M., Chandran, A.V., Prakash, S., Vijayan, M., Chatterji, D.(2017) Structure 25: 1449-1454.e3
- PubMed: 28823472
- DOI: https://doi.org/10.1016/j.str.2017.07.006
- Primary Citation of Related Structures:
5H46 - PubMed Abstract:
Proteins of the ferritin family are ubiquitous in living organisms. With their spherical cage-like structures they are the iron storehouses in cells. Subfamilies of ferritins include 24-meric ferritins and bacterioferritins (maxiferritins), and 12-meric Dps (miniferritins). Dps safeguards DNA by direct binding, affording physical protection and safeguards from free radical-mediated damage by sequestering iron in its core. The maxiferritins can oxidize and store iron but cannot bind DNA. Here we show that a mutation at a critical interface in Dps alters its assembly from the canonical 12-mer to a ferritin-like 24-mer under crystallization. This structural switch was attributed to the conformational alteration of a highly conserved helical loop and rearrangement of the C-terminus. Our results demonstrate a novel concept of mutational switch between related protein subfamilies and corroborate the popular model for evolution by which subtle substitutions in an amino acid sequence lead to diversification among proteins.
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India.
Organizational Affiliation:
