Co-crystal structure of Helicobacter pylori biotin protein ligase with biotinyl-5-ATP.

Helicobacter pylori, a type 1 carcinogen that causes human gastric ulcers and cancer, is a priority target of the Seattle Structural Genomics Center for Infectious Disease (SSGCID). These efforts include determining the structures of potential H. pylori therapeutic targets.

Structure of Plasmodium vivaxN-myristoyltransferase with inhibitor IMP-1088: exploring an NMT inhibitor for antimalarial therapy.

Plasmodium vivax, a significant contributor to global malaria cases, poses an escalating health burden on a substantial portion of the world's population. The increasing spread of P. vivax because of climate change underscores the development of new and rational drug-discovery approaches.

Exquisite selectivity of griselimycin extends to beta subunit of DNA polymerases from Gram-negative bacterial pathogens.

Griselimycin, a cyclic depsidecapeptide produced by Streptomyces griseus, is a promising lead inhibitor of the sliding clamp component of bacterial DNA polymerases (β-subunit of Escherichia coli DNA pol III). It was previously shown to inhibit the Mycobacterium tuberculosis β-clamp with remarkably high affinity and selectivity - the peptide lacks any interaction with the human sliding clamp. Here, we used a structural genomics approach to address the prospect of broader-spectrum inhibition, in particular of β-clamps from Gram-negative bacterial targets.

Structural and functional characterization of FabG4 from Mycolicibacterium smegmatis.

The rise in antimicrobial resistance is a global health crisis and necessitates the development of novel strategies to treat infections. For example, in 2022 tuberculosis (TB) was the second leading infectious killer after COVID-19, with multi-drug-resistant strains of TB having an ∼40% fatality rate. Targeting essential biosynthetic pathways in pathogens has proven to be successful for the development of novel antimicrobial treatments.

Crystal structure and biophysical characterization of IspD from Burkholderia thailandensis and Mycobacterium paratuberculosis.

The methylerythritol phosphate (MEP) pathway is a metabolic pathway that produces the isoprenoids isopentyl pyrophosphate and dimethylallyl pyrophosphate. Notably, the MEP pathway is present in bacteria and not in mammals, which makes the enzymes of the MEP pathway attractive targets for discovering new anti-infective agents due to the reduced chances of off-target interactions leading to side effects. There are seven enzymes in the MEP pathway, the third of which is IspD.

Discovery and Characterization of Potent, Efficacious, Orally Available Antimalarial Plasmepsin X Inhibitors and Preclinical Safety Assessment of .

Plasmepsin X (PMX) is an essential aspartyl protease controlling malaria parasite egress and invasion of erythrocytes, development of functional liver merozoites (prophylactic activity), and blocking transmission to mosquitoes, making it a potential multistage drug target. We report the optimization of an aspartyl protease binding scaffold and the discovery of potent, orally active PMX inhibitors with in vivo antimalarial efficacy. Incorporation of safety evaluation early in the characterization of PMX inhibitors precluded compounds with a long human half-life () to be developed.

Broad-spectrum in vitro activity of macrophage infectivity potentiator inhibitors against Gram-negative bacteria and Leishmania major.

Background: The macrophage infectivity potentiator (Mip) protein, which belongs to the immunophilin superfamily, is a peptidyl-prolyl cis/trans isomerase (PPIase) enzyme. Mip has been shown to be important for virulence in a wide range of pathogenic microorganisms. It has previously been demonstrated that small-molecule compounds designed to target Mip from the Gram-negative bacterium Burkholderia pseudomallei bind at the site of enzymatic activity of the protein, inhibiting the in vitro activity of Mip.

Structures of plasmepsin X from Plasmodium falciparum reveal a novel inactivation mechanism of the zymogen and molecular basis for binding of inhibitors in mature enzyme.

Plasmodium falciparum plasmepsin X (PfPMX), involved in the invasion and egress of this deadliest malarial parasite, is essential for its survival and hence considered as an important drug target. We report the first crystal structure of PfPMX zymogen containing a novel fold of its prosegment. A unique twisted loop from the prosegment and arginine 244 from the mature enzyme is involved in zymogen inactivation; such mechanism, not previously reported, might be common for apicomplexan proteases similar to PfPMX.

Naegleria fowleri: Protein structures to facilitate drug discovery for the deadly, pathogenic free-living amoeba.

Naegleria fowleri is a pathogenic, thermophilic, free-living amoeba which causes primary amebic meningoencephalitis (PAM). Penetrating the olfactory mucosa, the brain-eating amoeba travels along the olfactory nerves, burrowing through the cribriform plate to its destination: the brain's frontal lobes. The amoeba thrives in warm, freshwater environments, with peak infection rates in the summer months and has a mortality rate of approximately 97%.

Crystal structure of acetoacetyl-CoA reductase from Rickettsia felis.

Rickettsia felis, a Gram-negative bacterium that causes spotted fever, is of increasing interest as an emerging human pathogen. R. felis and several other Rickettsia strains are classed as National Institute of Allergy and Infectious Diseases priority pathogens.

Discovery of Adamantane Carboxamides as Ebola Virus Cell Entry and Glycoprotein Inhibitors.

We identified and explored the structure-activity-relationship (SAR) of an adamantane carboxamide chemical series of Ebola virus (EBOV) inhibitors. Selected analogs exhibited half-maximal inhibitory concentrations (EC values) of ∼10-15 nM in (VSV) pseudotyped EBOV (pEBOV) infectivity assays, low hundred nanomolar EC activity against wild type EBOV, aqueous solubility >20 mg/mL, and attractive metabolic stability in human and nonhuman liver microsomes. X-ray cocrystallographic characterizations of a lead compound with the EBOV glycoprotein (GP) established the EBOV GP as a target for direct compound inhibitory activity and further provided relevant structural models that may assist in identifying optimized therapeutic candidates.

Crystal structures of thiamine monophosphate kinase from Acinetobacter baumannii in complex with substrates and products.

Thiamine monophosphate kinase (ThiL) catalyzes the last step of thiamine pyrophosphate (TPP) synthesis, the ATP-dependent phosphorylation of thiamine monophosphate (TMP) to thiamine pyrophosphate. We solved the structure of ThiL from the human pathogen A. baumanii in complex with a pair of substrates TMP and a non-hydrolyzable adenosine triphosphate analog, and in complex with a pair of products TPP and adenosine diphosphate.

Ab initio structure solution of a proteolytic fragment using ARCIMBOLDO.

Crystal structure determination requires solving the phase problem. This can be accomplished using ab initio direct methods for small molecules and macromolecules at resolutions higher than 1.2 Å, whereas macromolecular structure determination at lower resolution requires either molecular replacement using a homologous structure or experimental phases using a derivative such as covalent labeling (for example selenomethionine or mercury derivatization) or heavy-atom soaking (for example iodide ions).

Crystal structure of chorismate mutase from Burkholderia phymatum.

The bacterium Burkholderia phymatum is a promiscuous symbiotic nitrogen-fixating bacterium that belongs to one of the largest groups of Betaproteobacteria. Other Burkholderia species are known to cause disease in plants and animals, and some are potential agents for biological warfare. Structural genomics efforts include characterizing the structures of enzymes from pathways that can be targeted for drug development.

Structure of acid deoxyribonuclease.

Deoxyribonuclease II (DNase II) is also known as acid deoxyribonuclease because it has optimal activity at the low pH environment of lysosomes where it is typically found in higher eukaryotes. Interestingly, DNase II has also been identified in a few genera of bacteria and is believed to have arisen via horizontal transfer. Here, we demonstrate that recombinant Burkholderia thailandensis DNase II is highly active at low pH in the absence of divalent metal ions, similar to eukaryotic DNase II.

Ligand co-crystallization of aminoacyl-tRNA synthetases from infectious disease organisms.

Aminoacyl-tRNA synthetases (aaRSs) charge tRNAs with their cognate amino acid, an essential precursor step to loading of charged tRNAs onto the ribosome and addition of the amino acid to the growing polypeptide chain during protein synthesis. Because of this important biological function, aminoacyl-tRNA synthetases have been the focus of anti-infective drug development efforts and two aaRS inhibitors have been approved as drugs. Several researchers in the scientific community requested aminoacyl-tRNA synthetases to be targeted in the Seattle Structural Genomics Center for Infectious Disease (SSGCID) structure determination pipeline.