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subsp. (), a Gram-negative bacterium causing furunculosis in fish, produces the siderophores acinetobactin and amonabactins in order to extract iron from its hosts. While the synthesis and transport of both systems is well understood, the regulation pathways and conditions necessary for the production of each one of these siderophores are not clear. The acinetobactin gene cluster carries a gene () encoding a putative sigma factor belonging to group 4 σ factors, or, the ExtraCytoplasmic Function (ECF) group. By generating a null mutant, we demonstrate that AsbI is a key regulator that controls acinetobactin acquisition in , since it directly regulates the expression of the outer membrane transporter gene and other genes necessary for Fe-acinetobactin transport. Furthermore, AsbI regulatory functions are interconnected with other iron-dependent regulators, such as the Fur protein, as well as with other sigma factors in a complex regulatory network.
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http://dx.doi.org/10.3390/ijms24119672 | DOI Listing |
J Child Psychol Psychiatry
September 2025
Department of Neurosciences, Research Group Psychiatry, Center for Clinical Psychiatry, KU Leuven, Leuven, Belgium.
Background: Previous research suggests that sexual minorities are at higher risk for psychotic experiences, possibly due to repeated social defeat experiences. However, empirical research investigating this hypothesis is largely lacking. This study examined how experiences of "feeling excluded" and "not belonging" impact the prospective development of psychotic experiences in an adolescent sexual minority group, defined here as non-heterosexual attraction to others.
View Article and Find Full Text PDFChem Sci
August 2025
Department of Chemistry, University of Houston Houston Texas 77204 USA
Quantum mechanical tunnelling significantly influences the reactivity of strained ring systems, yet strategies for controlling such reactivity remain largely unexplored. Here, we identify geminal hyperconjugation, , electron delocalization between σ-bonds attached to a common atom, as a decisive electronic factor in governing heavy-atom tunnelling reactions involving three-membered rings. We illustrate this through a case study of the oxepin (1') ⇌ benzene oxide (1) equilibrium, recently shown to undergo solvent-controlled tunnelling at 3 K (, 2020, , 20318).
View Article and Find Full Text PDFPLoS Pathog
September 2025
Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, India.
Host-derived short-chain fatty acids (SCFAs) are essential for Salmonella Typhimurium (STM) virulence. Formate, an SCFA found in the ileum, enhances STM invasion, but the role of the intracellular formate pool in STM pathogenesis remains poorly understood. Deletion of the pflB gene, which encodes pyruvate-formate lyase, depletes this intracellular pool, leading to reduced flagellation and increased expression of pathogenicity island-1 genes (hilA and prgH).
View Article and Find Full Text PDFFEBS J
September 2025
Department of Chemical Sciences, Bose Institute, Kolkata, India.
The gene regulation in Mycobacterium tuberculosis by different sigma factors, including the principal sigma factor, sigmaA (SigA), is poorly understood. Here, we have developed a modified genomic systematic evolution of ligands by exponential enrichment (SELEX)-Seq approach that identifies 350 new SigA-binding sites in M. tuberculosis.
View Article and Find Full Text PDFmSphere
September 2025
Instituto de Tecnologia Química e Biológica António Xavier, Oeiras, Portugal.
Most strains of produce two toxins, TcdA and TcdB, which are mainly responsible for the disease symptoms. TcdA and TcdB are coded for by genes in the pathogenicity locus (PaLoc). Some epidemic strains, however, such as R20291, of ribotype 027, additionally produce a binary toxin, CDT, coded for by genes in the CDT locus (CdtLoc).
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