The Pasteurella multocida znuACB genes encoding a high-affinity zinc-uptake system have been identified and cloned. In contrast to what happens in Escherichia coli, znuA is not physically linked to znuCB. Through lacZ transcriptional fusions it has been demonstrated that zinc negatively regulates both znuA and znuCB operons. Nevertheless, and contrary to that determined so far for all other znuACB bacterial systems known, P. multocida znuACB genes are not under control of the zur gene, which is absent in this bacterial species, but rather are under its iron-uptake regulator (fur) gene. Furthermore, construction of defective mutants has demonstrated that P. multocida znuA and znuCB transcriptional units are required for virulence of this organism in a mouse model.
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http://dx.doi.org/10.1016/S0378-1097(03)00131-9 | DOI Listing |
J Lipid Res
June 2024
School of Medicine, University of St. Andrews, St. Andrews, UK. Electronic address:
Zinc is required for virtually all biological processes. In plasma, Zn is predominantly transported by human serum albumin (HSA), which possesses two Zn-binding sites of differing affinities (sites A and B). Fatty acids (FAs) are also transported by HSA, with seven structurally characterized FA-binding sites (named FA1-FA7) known.
View Article and Find Full Text PDFJ Fungi (Basel)
January 2024
Laboratory of Molecular Biology, Institute of Biological Sciences, Federal University of Goiás, Goiânia 74690-900, GO, Brazil.
The survival of pathogenic fungi in the host after invasion depends on their ability to obtain nutrients, which include the transition metal zinc. This essential micronutrient is required to maintain the structure and function of various proteins and, therefore, plays a critical role in various biological processes. The host's nutritional immunity limits the availability of zinc to pathogenic fungi mainly by the action of calprotectin, a component of neutrophil extracellular traps.
View Article and Find Full Text PDFBiochemistry
March 2024
Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States.
Bacterial cells tightly regulate the intracellular concentrations of essential transition metal ions by deploying a panel of metal-regulated transcriptional repressors and activators that bind to operator-promoter regions upstream of regulated genes. Like other zinc uptake regulator (Zur) proteins, Zur represses transcription of its regulon when Zn is replete and binds more weakly to DNA when Zn is limiting. Previous studies established that Zur proteins are homodimeric and harbor at least two metal sites per protomer or four per dimer.
View Article and Find Full Text PDFBr J Biomed Sci
November 2023
College of Life Sciences, Birmingham City University, Birmingham, United Kingdom.
is an opportunistic pathogen that is primarily associated with severe respiratory infections in people with cystic fibrosis. These bacteria have significant intrinsic resistance to antimicrobial therapy, and there is a need for more effective treatments. Bacterial zinc uptake and homeostasis systems are attractive targets for new drugs, yet our understanding of how bacteria acquire and utilise zinc remains incomplete.
View Article and Find Full Text PDFMetallomics
August 2023
Department of Chemistry, University of Houston, Houston, TX 77204, USA.
As the second most abundant transition element and a crucial cofactor for many proteins, zinc is essential for the survival of all living organisms. To maintain required zinc levels and prevent toxic overload, cells and organisms have a collection of metal transport proteins for uptake and efflux of zinc. In bacteria, metal transport proteins are well defined for model organisms and many pathogens, but fewer studies have explored metal transport proteins, including those for zinc, in commensal bacteria from the gut microbiota.
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