Mariapina D'Onofrio

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The second domain of the human Menkes protein (MNK2), formed by 72 residues, has been expressed in Escherichia coli, and its structure has been determined by NMR in both the apo and copper-loaded forms. The structures, obtained with (13)C- and (15)N-labeled samples, are of high quality with backbone rmsd values of 0.51 and 0.41 A and CYANA target functions(More)
A putative partner of the already characterized CopZ from Bacillus subtilis was found, both proteins being encoded by genes located in the same operon. This new protein is highly homologous to eukaryotic and prokaryotic P-type ATPases such as CopA, Ccc2 and Menkes proteins. The N-terminal region of this protein contains two soluble domains constituted by(More)
To identify previously unknown small molecules that inhibit cell cycle machinery, we performed a chemical genetic screen in Xenopus extracts. One class of inhibitors, termed ubistatins, blocked cell cycle progression by inhibiting cyclin B proteolysis and inhibited degradation of ubiquitinated Sic1 by purified proteasomes. Ubistatins blocked the binding of(More)
The solution structure of the copper-free state of a monomeric form of superoxide dismutase (153 amino acids) was determined through (13)C and (15)N labeling. The protein contained two mutations at the native subunit-subunit interface (F50E and G51E) to obtain a soluble monomeric species and a mutation in the active site channel (E133Q). About 93% of carbon(More)
In group B Streptococcus (GBS), 3 structurally distinct types of pili have been discovered as potential virulence factors and vaccine candidates. The pilus-forming proteins are assembled into high-molecular-weight polymers via a transpeptidation mechanism mediated by specific class C sortases. Using a multidisciplinary approach including bioinformatics,(More)
Gram-positive bacteria build pili on their cell surface via a class C sortase-catalyzed transpeptidation mechanism from pilin protein substrates. Despite the availability of several crystal structures, pilus-related C sortases remain poorly characterized to date, and their mechanisms of transpeptidation and regulation need to be further investigated. The(More)
The investigation of multi-site ligand-protein binding and multi-step mechanisms is highly demanding. In this work, advanced NMR methodologies such as 2D (1)H-(15)N line-shape analysis, which allows a reliable investigation of ligand binding occurring on micro- to millisecond timescales, have been extended to model a two-step binding mechanism. The(More)
Group B Streptococcus (GBS) expresses 3 structurally distinct pilus types (1, 2a, and 2b) identified as important virulence factors and vaccine targets. These pili are heterotrimeric polymers, covalently assembled on the cell wall by sortase (Srt) enzymes. We investigated the pilus-2b biogenesis mechanism by using a multidisciplinary approach integrating(More)
Human liver fatty acid binding protein (hL-FABP) has been reported to act as an intracellular shuttle of lipid molecules, thus playing a central role in systemic metabolic homeostasis. The involvement of hL-FABP in the transport of bile salts has been postulated but scarcely investigated. Here we describe a thorough NMR investigation of glycocholate (GCA)(More)
Bile acid binding proteins (BABPs) are cytosolic lipid chaperones contributing to the maintenance of bile acid homeostasis and functional distribution within the cell. Liver BABPs act in parallel with ileal transporters to ensure vectorial transport of bile salts in hepatocytes and enterocytes, respectively. We describe the investigation of ligand binding(More)