Unraveling the molecular determinants of a rare human mitochondrial disorder caused by the P144L mutation of FDX2.

Episodic mitochondrial myopathy with or without optic atrophy and reversible leukoencephalopathy (MEOAL) is a rare, orphan autosomal recessive disorder caused by mutations in ferredoxin-2 (FDX2), which is a [2Fe-2S] cluster-binding protein participating in the formation of iron-sulfur clusters in mitochondria. In this biosynthetic pathway, FDX2 works as electron donor to promote the assembly of both [2Fe-2S] and [4Fe-4S] clusters. A recently identified missense mutation of MEOAL is the homozygous mutation c.

A Structural Investigation of the Interaction between a GC-376-Based Peptidomimetic PROTAC and Its Precursor with the Viral Main Protease of Coxsackievirus B3.

The conservation of the main protease in viral genomes, combined with the absence of a homologous protease in humans, makes this enzyme family an ideal target for developing broad-spectrum antiviral drugs with minimized host toxicity. GC-376, a peptidomimetic 3CL protease inhibitor, has shown significant efficacy against coronaviruses. Recently, a GC-376-based PROTAC was developed to target and induce the proteasome-mediated degradation of the dimeric SARS-CoV-2 3CL protein.

Structural aspects of iron‑sulfur protein biogenesis: An NMR view.

Over the last decade, structural aspects involving iron‑sulfur (Fe/S) protein biogenesis have played an increasingly important role in understanding the high mechanistic complexity of mitochondrial and cytosolic machineries maturing Fe/S proteins. In this respect, solution NMR has had a significant impact because of its ability to monitor transient protein-protein interactions, which are abundant in the networks of pathways leading to Fe/S cluster biosynthesis and transfer, as well as thanks to the developments of paramagnetic NMR in both terms of new methodologies and accurate data interpretation. Here, we review the use of solution NMR in characterizing the structural aspects of human Fe/S proteins and their interactions in the framework of Fe/S protein biogenesis.

Development of a GC-376 Based Peptidomimetic PROTAC as a Degrader of 3-Chymotrypsin-like Protease of SARS-CoV-2.

We have applied a proteolysis targeting chimera (PROTAC) technology to obtain a peptidomimetic molecule able to trigger the degradation of SARS-CoV-2 3-chymotrypsin-like protease (3CL). The PROTAC molecule was designed by conjugating a GC-376 based dipeptidyl 3CL ligand to a pomalidomide moiety through a piperazine-piperidine linker. NMR and crystallographic data complemented with enzymatic and cellular studies showed that (i) the dipeptidyl moiety of PROTAC binds to the active site of the dimeric state of SARS-CoV-2 3CL forming a reversible covalent bond with the sulfur atom of catalytic Cys145, (ii) the linker and the pomalidomide cereblon-ligand of PROTAC protrude from the protein, displaying a high degree of flexibility and no interactions with other regions of the protein, and (iii) PROTAC reduces the protein levels of SARS-CoV-2 3CL in cultured cells.

Structural Plasticity of NFU1 Upon Interaction with Binding Partners: Insights into the Mitochondrial [4Fe-4S] Cluster Pathway.

In humans, the biosynthesis and trafficking of mitochondrial [4Fe-4S] clusters is a highly coordinated process that requires a complex protein machinery. In a mitochondrial pathway among various proposed to biosynthesize nascent [4Fe-4S] clusters, two [2Fe-2S] clusters are converted into a [4Fe-4S] cluster on a ISCA1-ISCA2 complex. Along this pathway, this cluster is then mobilized from this complex to mitochondrial apo recipient proteins with the assistance of accessory proteins.