5h46

Publication Abstract from PubMed

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.

A Mutation Directs the Structural Switch of DNA Binding Proteins under Starvation to a Ferritin-like Protein Cage.,Williams SM, Chandran AV, Prakash S, Vijayan M, Chatterji D Structure. 2017 Aug 2. pii: S0969-2126(17)30221-6. doi:, 10.1016/j.str.2017.07.006. PMID:28823472^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.