Inhibition of L-Threonine Dehydrogenase from Trypanosoma cruzi reduces glycine and acetate production and interferes with parasite growth and viability.

Trypanosoma cruzi is a flagellated protozoan and the etiological agent of Chagas Disease, a neglected tropical disease described by Carlos Chagas in 1909 that remains without appropriate diagnostics and treatment. Throughout its life cycle, T. cruzi undergoes through many different environments, requiring adaptation of its metabolism to different nutrition sources.

Discovery and structural characterization of chicoric acid as a SARS-CoV-2 nucleocapsid protein ligand and RNA binding disruptor.

The nucleocapsid (N) protein plays critical roles in coronavirus genome transcription and packaging, representing a key target for the development of novel antivirals, and for which structural information on ligand binding is scarce. We used a novel fluorescence polarization assay to identify small molecules that disrupt the binding of the N protein to a target RNA derived from the SARS-CoV-2 genome packaging signal. Several phenolic compounds, including L-chicoric acid (CA), were identified as high-affinity N-protein ligands.

Malic Enzyme Is the Target for Sulfonamide Hits from the GSK Chagas Box.

Chagas disease, an infectious condition caused by , lacks treatment with drugs with desired efficacy and safety profiles. To address this unmet medical need, a set of trypanocidal compounds were identified through a large multicenter phenotypic-screening initiative and assembled in the GSK Chagas Box. In the present work, we report the screening of the Chagas Box against malic enzymes (MEs) and the identification of three potent inhibitors of its cytosolic isoform (TcMEc).

Molecular basis for diaryldiamine selectivity and competition with tRNA in a type 2 methionyl-tRNA synthetase from a Gram-negative bacterium.

Gram-negative bacteria are responsible for a variety of human, animal, and plant diseases. The spread of multidrug-resistant Gram-negative bacteria poses a challenge to disease control and highlights the need for novel antimicrobials. Owing to their critical role in protein synthesis, aminoacyl-tRNA synthetases, including the methionyl-tRNA synthetases MetRS1 and MetRS2, are attractive drug targets.

C7orf59/LAMTOR4 phosphorylation and structural flexibility modulate Ragulator assembly.

Ragulator is a pentamer composed of p18, MP1, p14, C7orf59, and hepatitis B virus X-interacting protein (HBXIP; LAMTOR 1-5) which acts as a lysosomal scaffold of the Rag GTPases in the amino acid sensitive branch of TORC1 signaling. Here, we present the crystal structure of human HBXIP-C7orf59 dimer (LAMTOR 4/5) at 2.9 Å and identify a phosphorylation site on C7orf59 which modulates its interaction with p18.

Discovery of antichagasic inhibitors by high-throughput screening with Trypanosoma cruzi glucokinase.

A high-throughput screening (HTS) campaign was carried out for Trypanosoma cruzi glucokinase (TcGlcK), a potential drug-target of the pathogenic protozoan parasite. Glycolysis and the pentose phosphate pathway (PPP) are important metabolic pathways for T. cruzi and the inhibition of the glucose kinases (i.

Role of the Citrus sinensis RNA deadenylase CsCAF1 in citrus canker resistance.

Poly(A) tail shortening is a critical step in messenger RNA (mRNA) decay and control of gene expression. The carbon catabolite repressor 4 (CCR4)-associated factor 1 (CAF1) component of the CCR4-NOT deadenylase complex plays an essential role in mRNA deadenylation in most eukaryotes. However, while CAF1 has been extensively investigated in yeast and animals, its role in plants remains largely unknown.

Structure-function relationship of a citrus salicylate methylesterase and role of salicylic acid in citrus canker resistance.

Salicylic acid (SA) and its methyl ester, methyl salicylate (MeSA) are well known inducers of local and systemic plant defense responses, respectively. MeSA is a major mediator of systemic acquired resistance (SAR) and its conversion back into SA is thought to be required for SAR. In many plant species, conversion of MeSA into SA is mediated by MeSA esterases of the SABP2 family.

Adenosine Kinase couples sensing of cellular potassium depletion to purine metabolism.

Adenosine Kinase (ADK) regulates the cellular levels of adenosine (ADO) by fine-tuning its metabolic clearance. The transfer of γ-phosphate from ATP to ADO by ADK involves regulation by the substrates and products, as well as by Mg and inorganic phosphate. Here we present new crystal structures of mouse ADK (mADK) binary (mADK:ADO; 1.

First Nonphosphorylated Inhibitors of Phosphoglucose Isomerase Identified by Chemical Library Screening.

Human African trypanosomiasis, Chagas disease, and leishmaniasis are human infections caused by kinetoplastid parasites of the genera Trypanosoma and Leishmania. Besides their severity and global impact, treatments are still challenging. Currently available drugs have important limitations, highlighting the urgent need to develop new drugs.

From a metagenomic source to a high-resolution structure of a novel alkaline esterase.

Esterases catalyze the cleavage and formation of ester bonds and are members of the diverse family of α/β hydrolase fold. They are useful in industries from different sectors, such as food, detergent, fine chemicals, and biofuel production. In a previous work, 30 positive clones for lipolytic activity were identified from a metagenomic library of a microbial consortium specialized in diesel oil degradation.

The structure of a Trypanosoma cruzi glucose-6-phosphate dehydrogenase reveals differences from the mammalian enzyme.

The enzyme glucose-6-phosphate dehydrogenase from Trypanosoma cruzi (TcG6PDH) catalyses the first step of the pentose phosphate pathway (PPP) and is considered a promising target for the discovery of a new drug against Chagas diseases. In the present work, we describe the crystal structure of TcG6PDH obtained in a ternary complex with the substrate β-d-glucose-6-phosphate (G6P) and the reduced 'catalytic' cofactor NADPH, which reveals the molecular basis of substrate and cofactor recognition. A comparison with the homologous human protein sheds light on differences in the cofactor-binding site that might be explored towards the design of new NADP(+) competitive inhibitors targeting the parasite enzyme.

Est16, a New Esterase Isolated from a Metagenomic Library of a Microbial Consortium Specializing in Diesel Oil Degradation.

Lipolytic enzymes have attracted attention from a global market because they show enormous biotechnological potential for applications such as detergent production, leather processing, cosmetics production, and use in perfumes and biodiesel. Due to the intense demand for biocatalysts, a metagenomic approach provides methods of identifying new enzymes. In this study, an esterase designated as Est16 was selected from 4224 clones of a fosmid metagenomic library, revealing an 87% amino acid identity with an esterase/lipase (accession number ADM63076.

Discovery of new uncompetitive inhibitors of glucose-6-phosphate dehydrogenase.

The enzyme glucose-6-phosphate dehydrogenase (G6PDH) catalyzes the first step of the oxidative branch of the pentose phosphate pathway, which provides cells with NADPH, an essential cofactor for many biosynthetic pathways and antioxidizing enzymes. In Trypanosoma cruzi, the G6PDH has being pursued as a relevant target for the development of new drugs against Chagas disease. At present, the best characterized inhibitors of T.

Structural role of the active-site metal in the conformation of Trypanosoma brucei phosphoglycerate mutase.

Phosphoglycerate mutases (PGAMs) participate in both the glycolytic and the gluconeogenic pathways in reversible isomerization of 3-phosphoglycerate and 2-phosphoglycerate. PGAMs are members of two distinct protein families: enzymes that are dependent on or independent of the 2,3-bisphosphoglycerate cofactor. We determined the X-ray structure of the monomeric Trypanosoma brucei independent PGAM (TbiPGAM) in its apoenzyme form, and confirmed this observation by small angle X-ray scattering data.