The enzyme S-adenosylmethionine (SAM) synthetase, the Escherichia coli metK gene product, produces SAM, the cell's major methyl donor. We show here that SAM synthetase activity is induced by leucine and repressed by Lrp, the leucine-responsive regulatory protein. When SAM synthetase activity falls below a certain critical threshold, the cells produce long filaments with regularly distributed nucleoids. Expression of a plasmid-carried metK gene prevents filamentation and restores normal growth to the metK mutant. This indicates that lack of SAM results in a division defect.
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http://dx.doi.org/10.1128/JB.180.14.3614-3619.1998 | DOI Listing |
Cell Death Dis
December 2024
Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.
The concept of Targeted Protein Degradation (TPD) has been introduced as an attractive alternative to the development of classical inhibitors. TPD can extend the range of proteins that can be pharmacologically targeted beyond the classical targets for small molecule inhibitors, as a binding pocket is required but its occupancy does not need to lead to inhibition. The method is based on either small molecules that simultaneously bind to a protein of interest and to a cellular E3 ligase and bring them in close proximity (molecular glue) or a bi-functional molecule synthesized from the chemical linkage of a target protein-specific small molecule and one that binds to an E3 ligase (Proteolysis Targeting Chimeras (PROTAC)).
View Article and Find Full Text PDFFront Plant Sci
November 2024
Department of Agronomy, Hetao College, Bayannur, China.
Introduction: S-adenosylmethionine (SAM), a key molecule in plant biology, plays an essential role in stress response and growth regulation. Despite its importance, the SAM synthetase gene family in sunflowers remains poorly understood.
Methods: In this study, the genes were identified from the sunflower genome.
The bursatellin-oxazinin family is a series of tyrosine-derived, nitrile-containing marine natural products from gastro-pod and bivalve molluscs. Although the first analogs were identified and associated with toxicity forty years ago, their biosynthetic origins were unknown. During an investigation of published mollusc genomes and transcriptomes, we serendipitously identified a putative bursatellin biosynthetic gene cluster (referred hereafter as the pathway).
View Article and Find Full Text PDFAcc Chem Res
September 2024
Department of Chemistry, L.S. Sam Skaggs Presidential Chair, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States.
ConspectusChemical synthesis as a tool to control the structure and properties of matter is at the heart of chemistry─from the synthesis of fine chemicals and polymers to drugs and solid-state materials. But as the field evolves to tackle larger and larger molecules and molecular complexes, the traditional tools of synthetic chemistry become limiting. In contrast, Mother Nature has developed very different strategies to create the macromolecules and molecular systems that make up the living cell.
View Article and Find Full Text PDFChem Biol Interact
August 2024
Department of Environmental Health Sciences, Yale School of Public Health, Yale University, New Haven, CT, 06510, USA. Electronic address:
Oxidative stress is intimately involved in the pathogenesis of fatty liver disease (FLD). A major factor contributing to oxidative stress is the depletion of the ubiquitous antioxidant glutathione (GSH). Unexpectedly, chronic GSH deficiency renders glutamate-cysteine ligase modifier subunit (Gclm)-null mice protected from fatty liver injuries.
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