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Analysis of NFU ‐1 metallocofactor binding‐site substitutions—impacts on iron–sulfur cluster coordination and protein structure and function
Author(s) -
Wesley Nathaniel A.,
Wachnowsky Christine,
Fidai Insiya,
Cowan J. A.
Publication year - 2017
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.14270
Subject(s) - iron–sulfur cluster , cluster (spacecraft) , cysteine , chemistry , ligand (biochemistry) , scaffold protein , binding site , function (biology) , biochemistry , genetics , plasma protein binding , mutation , missense mutation , biophysics , computational biology , biology , gene , receptor , signal transduction , enzyme , computer science , programming language
Iron–sulfur (Fe/S) clusters are ancient prosthetic groups found in numerous metalloproteins and are conserved across all kingdoms of life due to their diverse, yet essential functional roles. Genetic mutations to a specific subset of mitochondrial Fe/S cluster delivery proteins are broadly categorized as disease‐related under multiple mitochondrial dysfunction syndrome ( MMDS ), with symptoms indicative of a general failure of the metabolic system. Multiple mitochondrial dysfunction syndrome 1 ( MMDS 1) arises as a result of the missense mutation in NFU 1, an Fe/S cluster scaffold protein, which substitutes a glycine near the Fe/S cluster‐binding pocket to a cysteine (p.Gly208Cys). This substitution has been shown to promote protein dimerization such that cluster delivery to NFU 1 is blocked, preventing downstream cluster trafficking. However, the possibility of this additional cysteine, located adjacent to the cluster‐binding site, serving as an Fe/S cluster ligand has not yet been explored. To fully understand the consequences of this Gly208Cys replacement, complementary substitutions at the Fe/S cluster‐binding pocket for native and Gly208Cys NFU 1 were made, along with six other variants. Herein, we report the results of an investigation on the effect of these substitutions on both cluster coordination and NFU 1 structure and function. The data suggest that the G208C substitution does not contribute to cluster binding. Rather, replacement of the glycine at position 208 changes the oligomerization state as a result of global structural alterations that result in the downstream effects manifest as MMDS 1, but does not perturb the coordination chemistry of the Fe–S cluster.