D-cycloserine is an antibiotic which targets sequential bacterial cell wall peptidoglycan biosynthesis enzymes: alanine racemase and D-alanine:D-alanine ligase. By a combination of structural, chemical mechanistic studies here we show that the inhibition ligase by proceeds via distinct phosphorylated form drug. This insight reveals bimodal mechanism action for single on different enzyme has significance design future inhibitor molecules based this structure.

Aggregation and misfolding of the prion protein (PrP) are thought to be cause a family lethal neurodegenerative diseases affecting humans other animals. Although structures PrP from several species have been solved, still little is known about mechanisms that lead misfolded species. Here, we show region comprising hairpin formed by helices H2 H3 stable independently folded unit able retain its secondary tertiary structure also in absence rest sequence. We prove isolated H2H3 highly...

Crotamine is a component of the venom snake Crotalus durissus terrificus and it belongs to myotoxin protein family. It 42 amino acid toxin cross‐linked by three disulfide bridges characterized mild toxicity (LD 50 = 820 µg per 25 g body weight, i.p. injection) when compared other members same Nonetheless, possesses wide spectrum biological functions. In fact, besides being able specifically modify voltage‐sensitive Na + channel, has been suggested exhibit analgesic activity be myonecrotic....

Ataxin-1 (Atx1), a member of the polyglutamine (polyQ) expanded protein family, is responsible for spinocerebellar ataxia type 1. Requirements developing disease are polyQ expansion, nuclear localization and phosphorylation S776. Using combination bioinformatics, cell structural biology approaches, we have identified UHM ligand motif (ULM), present in proteins associated with splicing, C-terminus Atx1 shown that interacts influences function splicing factor U2AF65 via this motif. ULM...

Ataxin-1 (ATX1), a human protein responsible for spinocerebellar ataxia type 1 in humans, shares region of homology, named AXH module, with the apparently unrelated transcription factor HBP1. Here, we describe first characterisation module terms its structural properties and stability. By producing constructs spanning modules ATX1 HBP1 by comparing their properties, have identified minimal sufficient forming independently folded units (domains). Knowledge domain boundaries allows us to map...

The increasing global prevalence of drug resistance among many leading human pathogens necessitates both the development antibiotics with novel mechanisms action and a better understanding physiological activities preexisting clinically effective drugs. Inhibition peptidoglycan (PG) biosynthesis cross-linking has traditionally enjoyed immense success as an antibiotic target in multiple bacterial pathogens, except Mycobacterium tuberculosis, where it so far been underexploited. d-Cycloserine,...

Neisseria heparin binding antigen (NHBA), also known as GNA2132 (genome-derived 2132), is a surface-exposed lipoprotein from meningitidis that was originally identified by reverse vaccinology. It one the three main antigens of multicomponent vaccine against serogroup B meningitis (4CMenB), which has just completed phase III clinical trials in infants. In contrast to other two components, little about origin immunogenicity this antigen, and its ability induce strong cross-bactericidal...

Abstract ATP-phosphoribosyltransferase (ATP-PRT) is a hexameric enzyme in conformational equilibrium between an open and seemingly active state closed presumably inhibited form. The structure-function relationship of allosteric regulation this system still not fully understood. Here, we develop screening strategy for modulators ATP-PRT identify 3-(2-thienyl)- l- alanine (TIH) as activator enzyme. Kinetic analysis reveals co-occupancy the sites by TIH l -histidine. Crystallographic native...

Abstract Motivation: We have previously demonstrated that proteins may be aligned not only by sequence or structural homology, but also using their dynamical properties. Dynamics-based alignments are sensitive and powerful tools to compare even structurally dissimilar protein families. Here, we propose use this method predict regions involved in the binding of nucleic acids. used OB-fold, a motif known promote protein–nucleic acid interactions, validate our approach. Results: tested...

Ataxin-1 is a human protein responsible for spinocerebellar ataxia type 1, hereditary disease associated with aggregation and misfolding. Essential ataxin-1 the anomalous expansion of polyglutamine tract near N-terminus, but sequence-wise distant AXH domain modulates contributes to process. The also involved in nonpathologic functions protein, including variety intermolecular interactions other cellular partners. forms globular dimer solution displays dimers arrangement crystal asymmetric...

Polyglutamine tract-binding protein-1 (PQBP-1) is a 265-residue nuclear protein that involved in transcriptional regulation. In addition to its role the molecular pathology of polyglutamine expansion diseases, mutations are associated with X-linked mental retardation. PQBP-1 binds specifically glutamine repeat sequences and proline-rich regions, interacts RNA polymerase II spliceosomal U5-15kD. this work, we obtained biophysical characterization by employing complementary structural methods....

Anomalous expansion of a polymorphic tract in Ataxin-1 causes the autosomal dominant spinocerebellar ataxia type 1. In addition to polyglutamine expansion, requirements for development pathology are phosphorylation serine 776 and nuclear localization protein. The state is also crucial selection multiple partners. Here, we have used FRET an cell study interaction with spliceosome-associated U2AF65 adaptor 14-3-3 proteins. Using wild-type Ser776 mutants phosphomimetic aspartate alanine, show...

A main challenge for structural biologists is to understand the mechanisms that discriminate between molecular interactions and determine function. Here, we show how partner recognition of AXH domain transcriptional co-regulator ataxin-1 fine-tuned by a subtle balance self- hetero-associations. Ataxin-1 protein responsible hereditary spinocerebellar ataxia type 1, disease linked aggregation dysregulation. Expansion polyglutamine tract essential aggregation, but sequence-wise distant plays an...

Nerve Growth Factor (NGF), the prototype of neurotrophin family, is essential for maintenance and growth different neuronal populations. The X-ray crystal structure NGF known since early '90s shows a β-sandwich fold with extensive loops, involved in interaction its binding partners. Understanding dynamical properties these loops thus important molecular recognition. We present here combined solution NMR/molecular dynamics study which addresses question whether how much long are flexible...

The thioredoxin (Trx) from Bacillus acidocaldarius (BacTrx) was purified to homogeneity by anion-exchange chromatography and gel-filtration chromatography, based on its ability catalyse the dithiothreitol-dependent reduction of bovine insulin disulphides. protein has a molecular mass 11577 Da, determined electrospray spectrometry, pI 4.2, primary structure obtained automated Edman degradation after cleavage with trypsin cyanogen bromide. sequences known bacterial Trxs were aligned at active...

The biosynthetic pathway of peptidoglycan is essential for Mycobacterium tuberculosis. We report here the acetyltransferase substrate specificity and catalytic mechanism bifunctional N-acetyltransferase/uridylyltransferase from M. tuberculosis (GlmU). This enzyme responsible final two steps synthesis UDP- N-acetylglucosamine, which an precursor peptidoglycan, glucosamine 1-phosphate, acetyl-coenzyme A, uridine 5'-triphosphate. GlmU utilizes ternary complex formation to transfer acetyl A...

The thioredoxin (Trx) from Bacillus acidocaldarius (BacTrx), an eubacterium growing optimally at 333 K, is the first Trx described to date a moderate thermophilic source. To understand molecular basis of its thermostability, three‐dimensional structure in oxidized form was determined by NMR methods. A total 2276 1 H‐NMR derived distance constraints along with 23 hydrogen‐bonds, 72 φ and 27 χ torsion angle restraints, were used protocol employing simulated annealing followed restrained...

The leucine-rich repeat acidic nuclear protein (Anp32a/LANP) belongs to a family of evolutionarily-conserved phosphoproteins involved in complex network protein-protein interactions. In an effort understand the cellular role, we have investigated mode interaction Anp32a with its partners. As prerequisite, solved structure solution evolutionarily conserved N-terminal (LRR) domain and modeled interactions other proteins, taking PP2A as paradigmatic example. between LRR AXH ataxin-1 was probed...

The neurodegenerative disease spinocerebellar ataxia type 1 (SCA1) is caused by aggregation and misfolding of the ataxin-1 protein. While pathology correlates with mutations that lead to expansion a polyglutamine tract in protein, other regions contribute process as also non-expanded intrinsically aggregation-prone forms nuclear foci cell. Here, we have used combined approach based on FRET analysis, confocal microscopy vitro techniques map than establish importance dimerization...