Riboswitches are genetic control elements that usually reside in untranslated regions of messenger RNAs. These folded RNAs directly bind metabolites and undergo allosteric changes that modulate gene expression. A flavin mononucleotide (FMN)-dependent riboswitch from the ribDEAHT operon of Bacillus subtilis uses a transcription termination mechanism wherein formation of an RNA-FMN complex causes formation of an intrinsic terminator stem. We assessed the importance of RNA transcription speed and the kinetics of FMN binding to the nascent mRNA for riboswitch function. The riboswitch does not attain thermodynamic equilibrium with FMN before RNA polymerase needs to make a choice between continued transcription and transcription termination. Therefore, this riboswitch is kinetically driven, and functions more like a "molecular fuse." This reliance on the kinetics of ligand association and RNA polymerization speed might be common for riboswitches that utilize transcription termination mechanisms.
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http://dx.doi.org/10.1016/j.molcel.2005.02.032 | DOI Listing |
Int J Biol Macromol
January 2025
School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 102446, China. Electronic address:
Age-related cataract (ARC) remains the leading cause of blindness worldwide. Sagittaria sagittifolia polysaccharide (SSP) extract, a key component of Sagittaria sagittifolia L., exhibits anti-oxidant and anti-apoptotic effects with potential applications in ARC.
View Article and Find Full Text PDFJ Integr Neurosci
January 2025
Department of Anesthesia, Hangzhou Plastic Surgery Hospital, 310000 Hangzhou, Zhejiang, China.
Introduction: The effects of remimazolam (Re) in combination with andrographolide (AP) on learning, memory, and motor abilities in rats following cardiopulmonary bypass (CPB) surgery were studied.
Methods: We hypothesized that the combination of Re and AP could improve postoperative cognitive dysfunction (POCD) in rats after CPB by modulating nervous system inflammation. Cognitive function was assessed using the Morris Water Maze test, and the concentrations of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) in serum were measured by enzyme-linked immunosorbent assay (ELISA).
Int J Mol Sci
January 2025
Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei 10617, Taiwan.
During long-term peritoneal dialysis, peritoneal fibrosis (PF) often happens and results in ultrafiltration failure, which directly leads to the termination of dialysis. The accumulation of extracellular matrix produced from an increasing number of myofibroblasts was a hallmark characteristic of PF. To date, glucose degradation products (GDPs, i.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Azriele Faculty of Medicine in the Galilee, Bar-Ilan University, Safed 1311502, Israel.
Provoked vulvodynia (PV) is the leading cause of vulvar pain and dyspareunia. The etiology of PV is multifactorial and remains poorly understood. PV is associated with a history of repeated vulvar inflammation and is often accompanied by sensory neuromodulation as a result of activation of the metabotropic glutamate receptor 5 (mGluR5) in the sensory nerve terminals.
View Article and Find Full Text PDFGenes (Basel)
January 2025
Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
Background: Eukaryotic RNA polymerase I consists of 12 or 11 core subunits and three dissociable subunits, Rrn3, A34, and A49. The A34 and A49 subunits exist as a heterodimer. In silico analysis of the A34 family of transcription factors demonstrates a commonly shared domain structure despite a lack of sequence conservation, as well as N-terminal and C-terminal disordered regions.
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