Mammalian mitochondrial ribosomes (mitoribosomes) are responsible for synthesizing proteins that are essential for oxidative phosphorylation (ATP generation). Despite their common ancestry with bacteria, the composition and structure of the human mitoribosome and its translational factors are significantly different from those of their bacterial counterparts. The mammalian mitoribosome recycling factor (RRF) carries a mito-specific N terminus extension (NTE), which is necessary for the function of RRF Here we present a 3.9-Å resolution cryo-electron microscopic (cryo-EM) structure of the human 55S mitoribosome-RRF complex, which reveals α-helix and loop structures for the NTE that makes multiple mito-specific interactions with functionally critical regions of the mitoribosome. These include ribosomal RNA segments that constitute the peptidyl transferase center (PTC) and those that connect PTC with the GTPase-associated center and with mitoribosomal proteins L16 and L27. Our structure reveals the presence of a tRNA in the pe/E position and a rotation of the small mitoribosomal subunit on RRF binding. In addition, we observe an interaction between the pe/E tRNA and a mito-specific protein, mL64. These findings help understand the unique features of mitoribosome recycling.
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http://dx.doi.org/10.1073/pnas.1815675116 | DOI Listing |
Zhonghua Bing Li Xue Za Zhi
February 2025
Department of Pathology, the First Affiliated Hospital of Air Force Medical University, Xi'an 710032, China.
To investigate the clinicopathological features, diagnosis, genetic alterations, and biological behaviors of hamartomatous inverted hyperplastic polyp (HIHP) in the gastrointestinal tract. The clinical, sonographic, endoscopic and pathologic data of 10 HIHP cases diagnosed at the First Affiliated Hospital of Air Force Medical University, Xi'an, China from January 2013 to March 2024 were collected. Their clinicopathological features and histological morphology were analyzed.
View Article and Find Full Text PDFRadiol Clin North Am
March 2025
Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
Pediatric patients are affected by a wide variety of pulmonary vascular diseases ranging from congenital anomalies diagnosed at birth to acquired diseases that present later in childhood and into adolescence. While some pulmonary vascular diseases present similarly to those seen in adults, other forms are unique to children. Knowledge of the characteristic imaging features of these diseases is essential to facilitate prompt diagnosis and guide clinical management.
View Article and Find Full Text PDFRadiol Clin North Am
March 2025
Department of Pathology and Laboratory Medicine, University of Wisconsin, Madison, WI, USA. Electronic address:
Pulmonary hypertensive changes are commonly seen by the surgical pathologist, but the majority represents secondary changes due to some process extrinsic to the lung. Some primary, or idiopathic, vascular diseases result in unique pathologic changes including the plexiform lesion and venous hypertensive changes. Thromboembolic disease also shows unique pathologic features.
View Article and Find Full Text PDFJ Immunother Cancer
January 2025
Center for Immunotherapy, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
Evidence has shown that T-cell receptors (TCRs) that recognize the same epitopes may not be the exact TCR clonotypes but have slightly different TCR sequences. However, the changes in the genomic and transcriptomic signatures of these highly homologous T cells during immunotherapy remain unknown. Here, we examined the evolutionary features in circulating TCR clonotypes observed in tumors (tumor-infiltrating lymphocyte (TIL)-TCRs) by combining single-cell RNA/TCR sequencing of longitudinal blood samples and TCR sequencing of tumor tissue from a patient treated with anti-cytotoxic T-lymphocyte-associated protein 4/programmed cell death protein-1 therapy.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Core Facility Center "Arktika", Northern (Arctic) Federal University named after M.V. Lomonosov, Northern Dvina Emb., 17, Arkhangelsk 163002, Russian Federation. Electronic address:
Dioxane lignin (DL) is isolated from plant material under mild acidolysis conditions and is widely used in many studies as a representative sample of protolignin, an alternative to milled wood lignin (MWL). However, the structural changes caused by hydrolytic degradation reactions during DL extraction are still poorly understood. In this work, an integrated approach based on 2D NMR and high-resolution mass spectrometry was used to establish the features of the lignin structure on the example of pine lignin isolated using dioxane under various conditions: MWL, DL and "formaldehyde stabilized" lignin (LSF).
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