Natural transformation is the main means of horizontal genetic exchange in the obligate human pathogen Neisseria gonorrhoeae. Neisseria spp. have been shown to preferentially take up and transform their own DNA by recognizing a non-palindromic 10 or 12 nucleotide DNA uptake sequence (DUS10 or DUS12). We investigated the ability of the DUS12 to enhance single-stranded DNA (ssDNA) transformation. Given the non-palindromic nature of the DUS12, we tested whether both strands of the DUS equally enhance transformation. Recombinant single-stranded M13 phage harboring transforming DNA with the Watson DUS12, the Crick DUS12, or no DUS (DUS0) were constructed and circular ssDNA was purified. Southern blots of the purified DNA probed with strand-specific oligonucleotide probes showed > 10,000 : 1 ratio of ssDNA to contaminating dsDNA. The Crick strand of the DUS12 enhanced ssDNA transformation 180- to 470-fold over DUS0 ssDNA, whereas the Watson strand of the DUS only modestly enhanced ssDNA transformation in two strains of N. gonorrhoeae. These data confirm that ssDNA efficiently transforms N. gonorrhoeae, but that there is a strand preference and that part of this strand preference is a greater efficiency of the Crick strand of the DUS12 in enhancing transformation.
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http://dx.doi.org/10.1111/j.1574-6968.2012.02612.x | DOI Listing |
Biochemistry
January 2025
Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States.
In the wake of the pandemic, peptidyl protease inhibitors with Pro-based rigid Leu mimetics at the P position have emerged as potent drug candidates against the SARS-CoV-2 main protease. This success is intuitively attributed to the enhanced hydrophobic interactions and rigidity of Pro-based rigid Leu mimetics in the literature. However, the tertiary amide of proline P derivatives, which hinders the formation of a critical hydrogen bond with the enzyme active site, and the constrained PP conformation, which contradicts the protease preferred β-strand conformation, represent two overlooked disadvantages associated with these inhibitors over traditional inhibitors and, theoretically, should adversely affect their potency.
View Article and Find Full Text PDFActa Physiol (Oxf)
February 2025
Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Aim: Members of the claudin protein family are the major constituents of tight junction strands and determine the permeability properties of the paracellular pathway. In the kidney, each nephron segment expresses a distinct subset of claudins that form either barriers against paracellular solute transport or charge- and size-selective paracellular channels. It was the aim of the present study to determine and compare the permeation properties of these renal paracellular ion channel-forming claudins.
View Article and Find Full Text PDFRheumatology (Oxford)
January 2025
Department of Nephrology, The First Affiliated Hospital of Sun Yat-Sen University, People's Republic of China.
Objectives: Proliferative lupus nephritis (LN) is not uncommon in individuals with proteinuria < 0.5 g/24h, highlighting the importance of predicting proliferative nephritis for effective clinical management. We aimed to develop a predictive model for proliferative nephritis in this population.
View Article and Find Full Text PDFFront Zool
January 2025
Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou, 510260, People's Republic of China.
Background: Odorant binding proteins (OBPs) initiate the process of odorant perception. Numerous investigations have demonstrated that OBPs bind a broad variety of chemicals and are more likely to carry pheromones or odor molecules with high binding affinities. However, few studies have investigated its effects on insect behavior.
View Article and Find Full Text PDFAnimals (Basel)
January 2025
Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE-PSL, Université des Antilles, 75005 Paris, France.
The common bottlenose dolphin () exhibits significant intraspecific diversity globally, with distinct ecotypes identified in various regions. In the Guadeloupe archipelago, the citizen science NGO OMMAG has been monitoring these dolphins for over a decade, documenting two distinct morphotypes. This study investigates whether these morphotypes represent coastal and oceanic ecotypes, which have not been previously identified in the region.
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