bims-tricox 2023-11-05 papers

Issue of 2023‒11‒05
two papers selected by
Yash Verma, University of Zurich

Nat Commun. 2023 Oct 31. 14(1): 6961

The structure of a hibernating ribosome in a Lyme disease pathogen.

Manjuli R Sharma, Swati R Manjari, Ekansh K Agrawal, Pooja Keshavan, Ravi K Koripella, Soneya Majumdar, Ashley L Marcinkiewicz, Yi-Pin Lin, Rajendra K Agrawal, Nilesh K Banavali.

The spirochete bacterial pathogen Borrelia (Borreliella) burgdorferi (Bbu) affects more than 10% of the world population and causes Lyme disease in about half a million people in the US annually. Therapy for Lyme disease includes antibiotics that target the Bbu ribosome. Here we present the structure of the Bbu 70S ribosome obtained by single particle cryo-electron microscopy at 2.9 Å resolution, revealing a bound hibernation promotion factor protein and two genetically non-annotated ribosomal proteins bS22 and bL38. The ribosomal protein uL30 in Bbu has an N-terminal α-helical extension, partly resembling the mycobacterial bL37 protein, suggesting evolution of bL37 and a shorter uL30 from a longer uL30 protein. Its analogy to proteins uL30m and mL63 in mammalian mitochondrial ribosomes also suggests a plausible evolutionary pathway for expansion of protein content in mammalian mitochondrial ribosomes. Computational binding free energy predictions for antibiotics reflect subtle distinctions in antibiotic-binding sites in the Bbu ribosome. Discovery of these features in the Bbu ribosome may enable better ribosome-targeted antibiotic design for Lyme disease treatment.

DOI: https://doi.org/10.1038/s41467-023-42266-7

Trends Cell Biol. 2023 Oct 30. pii: S0962-8924(23)00208-8. [Epub ahead of print]

Mitochondrial complexome and import network.

Fabian den Brave, Uwe Schulte, Bernd Fakler, Nikolaus Pfanner, Thomas Becker.

Mitochondria perform crucial functions in cellular metabolism, protein and lipid biogenesis, quality control, and signaling. The systematic analysis of protein complexes and interaction networks provided exciting insights into the structural and functional organization of mitochondria. Most mitochondrial proteins do not act as independent units, but are interconnected by stable or dynamic protein-protein interactions. Protein translocases are responsible for importing precursor proteins into mitochondria and form central elements of several protein interaction networks. These networks include molecular chaperones and quality control factors, metabolite channels and respiratory chain complexes, and membrane and organellar contact sites. Protein translocases link the distinct networks into an overarching network, the mitochondrial import network (MitimNet), to coordinate biogenesis, membrane organization and function of mitochondria.

Keywords: cell organelles; energetics; metabolism; mitochondria; morphology; protein assembly; protein networks; protein sorting

DOI: https://doi.org/10.1016/j.tcb.2023.10.004