Publications by authors named "M Bellinzoni"
Article Synopsis
- The marine bacterium Halomonas titanicae KHS3 has a chemosensory pathway called HtChe2 that activates a diguanylate cyclase, altering colony appearance and enhancing biofilm formation, similar to the Wsp pathway in Pseudomonas.
- Research focused on Htc10, the only chemoreceptor in the HtChe2 system, revealing that it binds to guanine and hypoxanthine with specific interaction dynamics, which were characterized using advanced techniques like X-ray crystallography.
- The study found that when Htc10 was expressed in a Pseudomonas putida mutant lacking its own Wsp receptor, biofilm formation increased, especially with Htc10 ligands,
Pyruvate:quinone oxidoreductase (PQO) is a flavin-containing peripheral membrane enzyme catalyzing the decarboxylation of pyruvate to acetate and CO with quinone as an electron acceptor. Here, we investigate PQO activity in Corynebacterium glutamicum, examine purified PQO, and describe the crystal structure of the native enzyme and a truncated version. The specific PQO activity was highest in stationary phase cells grown in complex medium, lower in cells grown in complex medium containing glucose or acetate, and lowest in cells grown in minimal acetate-medium.
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- MbtI is a magnesium-dependent enzyme critical for iron acquisition in tuberculosis pathogens, making it a promising target for new anti-virulence therapies.
- Recent studies identified 5-phenylfuran-2-carboxylic acids as effective inhibitors of MbtI, with the first crystal structure of the enzyme-inhibitor complex published in 2020 revealing its open configuration.
- A new high-resolution crystal structure shows MbtI in a closed conformation with a furan derivative, allowing for a complete view of the active site, and indicates that the effectiveness of inhibitors may not depend on the enzyme's conformation.
Article Synopsis
- - Actinobacteria have a unique enzyme called OdhA that combines two functions (oxidative decarboxylation and succinyl transfer) in one protein, differing from many organisms that use three separate enzymes for the 2-oxoglutarate dehydrogenase complex.
- - High-resolution structural studies (cryo-EM and crystallography) reveal that OdhA forms an 800-kDa homohexamer with a distinct three-blade propeller shape, crucial for its function.
- - The study further explores how OdhA's acyltransferase and dehydrogenase domains interact and maintain their structure, while also detailing how the signalling protein OdhI regulates the function of this complex
In Corynebacterium glutamicum the protein kinase PknG phosphorylates OdhI and thereby abolishes the inhibition of 2-oxoglutarate dehydrogenase activity by unphosphorylated OdhI. Our previous studies suggested that PknG activity is controlled by the periplasmic binding protein GlnH and the transmembrane protein GlnX, because Δ and Δ mutants showed a growth defect on glutamine similar to that of a Δ mutant. We have now confirmed the involvement of GlnH and GlnX in the control of OdhI phosphorylation by analyzing the OdhI phosphorylation status and glutamate secretion in Δ and Δ mutants and by characterizing Δ suppressor mutants.
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