30S and 50S subunits, in the presence of either 20 mM Mg2+ or 6 mM Mg2+ and 5mM spermidine plus 25 mM putrescine, were observed to completely associate to form 70S monosomes as monitored by sucrose gradient sedimentation. Subunits maintained under the above ionic conditions were compared with 30S and 50S particles at low (6 mM) magnesium concentration with respect to the reactivity of individual ribosomal proteins to lactoperoxidase-catalyzed iodination. Altered reactivity to enzymatic iodination of ribosomal proteins S4, S9, S10, S14, S17, S19, and S20 in the small subunit of ribosomal proteins, L2, L9, L11, L27, and L30 in the large subunit following incubation with high magnesium or magnesium and polyamines suggests that a conformation change in both subunits accompanies the formation of 70S monosomes. The results further demonstrate that the effect of Mg2+ on subunit conformation is mimicked when polyamines are substituted for magnesium necessary for subunit association.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1139/o79-031 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The translation initiation factor eIF3M2 upregulates HEAT SHOCK PROTEIN 70 to maintain pollen tube membrane integrity during heat shock.
Plant Physiol
December 2024
Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, 165 00 Prague 6, Czech Republic.
Pollen germination and pollen tube (PT) growth are extremely sensitive to high temperatures. During heat stress (HS), global translation shuts down and favors the maintenance of the essential cellular proteome for cell viability and protection against protein misfolding. Here, we demonstrate that under normal conditions, the Arabidopsis (Arabidopsis thaliana) eukaryotic translation initiation factor subunit eif3m1/eif3m2 double mutant exhibits poor pollen germination, loss of PT integrity and an increased rate of aborted seeds.
View Article and Find Full Text PDFHeterogeneous and multiple conformational transition pathways between pseudoknots of the SARS-CoV-2 frameshift element.
Proc Natl Acad Sci U S A
January 2025
Department of Chemistry, New York University, New York, NY 10003.
Frameshifting is an essential mechanism employed by many viruses including coronaviruses to produce viral proteins from a compact RNA genome. It is facilitated by specific RNA folds in the frameshift element (FSE), which has emerged as an important therapeutic target. For SARS-CoV-2, a specific 3-stem pseudoknot has been identified to stimulate frameshifting.
View Article and Find Full Text PDFIRAP Drives Ribosomal Degradation to Refuel Energy for Platelet Activation during Septic Thrombosis.
Adv Sci (Weinh)
January 2025
State Key Laboratory of Trauma and Chemical Poisoning, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Army Medical University (Third Military Medical University), Chongqing, 400038, China.
Platelets play crucial roles in multiple pathophysiological processes after energy-dependent activation. It is puzzling how such a small cellular debris has abundant energy supply. In this study, it is shown that insulin-regulated aminopeptidase (IRAP), a type II transmembrane protein, is a key regulator for platelet activation by promoting energy regeneration during septic thrombosis.
View Article and Find Full Text PDFMetagenomic and Transcriptomic Analysis Reveals Crosstalk Between Intratumor Mycobiome and Hosts in Early-Stage Nonsmoking Lung Adenocarcinoma Patients.
Thorac Cancer
January 2025
Department of Thoracic Surgery and Lung Transplantation, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China.
Background: The mycobiome in the tumor microenvironment of non-smokers with early-stage lung adenocarcinoma (ES-LUAD) has been minimally investigated.
Methods: In this study, we conducted ultra-deep metagenomic and transcriptomic sequencing on 128 samples collected from 46 nonsmoking ES-LUAD patients and 41 healthy controls (HC), aiming to characterize the tumor-resident mycobiome and its interactions with the host.
Results: The results revealed that ES-LUAD patients exhibited fungal dysbiosis characterized by reduced species diversity and significant imbalances in specific fungal abundances.
Slowly evolving proteins support the monophyly of Craspedida (Choanoflagellatea) and a marine origin of choanoflagellates.
Protist
January 2025
School of Applied Sciences, University of Huddersfield, Huddersfield, United Kingdom. Electronic address:
Choanoflagellate species have been taxonomically divided upon the morphological and developmental basis of their extracellular coat (periplast). Species within the order Craspedida possess a purely organic periplast, whereas taxa of the order Acanthoecida have an additional silica based periplast termed the lorica. Whilst small-scale phylogenetic studies have recovered the two orders as monophyletic, recent phylogenomic analyses have rejected the monophyly of the craspedids.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!