PMID: 24687350 , Related PDB ids: 3ATU, 4B9Q, 4NJ4, 4KBO, 4ANI, 4JN4

Authors:

Amick J, Schlanger SE, Wachnowsky C, Moseng MA, Emerson CC, Dare M, Luo WI, Ithychanda SS, Nix JC, Cowan JA, Page RC, Misra S

Title:

Crystal structure of the nucleotide-binding domain of mortalin, the mitochondrial Hsp70 chaperone.

Journal:

Protein Sci. 2014 Mar 29. doi: 10.1002/pro.2466.

Abstract:

Mortalin, a member of the Hsp70-family of molecular chaperones, functions in a variety of processes including mitochondrial protein import and quality control, Fe-S cluster protein biogenesis, mitochondrial homeostasis, and regulation of p53. Mortalin is implicated in regulation of apoptosis, cell stress response, neurodegeneration, and cancer and is a target of the antitumor compound MKT-077. Like other Hsp70-family members, Mortalin consists of a nucleotide-binding domain (NBD) and a substrate-binding domain. We determined the crystal structure of the NBD of human Mortalin at 2.8 A resolution. Although the Mortalin nucleotide-binding pocket is highly conserved relative to other Hsp70 family members, we find that its nucleotide affinity is weaker than that of Hsc70. A Parkinson's disease-associated mutation is located on the Mortalin-NBD surface and may contribute to Mortalin aggregation. We present structure-based models for how the Mortalin-NBD may interact with the nucleotide exchange factor GrpEL1, with p53, and with MKT-077. Our structure may contribute to the understanding of disease-associated Mortalin mutations and to improved Mortalin-targeting antitumor compounds.