Many proteins synthesized in the cytoplasm ultimately function in non-cytoplasmic locations. In Escherichia coli, the general secretory (Sec) pathway transports the vast majority of these proteins. Two fundamental components of the Sec transport pathway are the SecYEG heterotrimeric complex that forms the channel through the cytoplasmic membrane, and SecA, the ATPase that drives the preprotein to and across the membrane. This review focuses on what is known about the oligomeric states of these core Sec components and how the oligomeric state might change during the course of the translocation of a preprotein.
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http://dx.doi.org/10.1016/j.bbamem.2006.08.013 | DOI Listing |
Nat Commun
January 2025
Department of Physics and Astronomy, Michigan State University, East Lansing, MI, USA.
DEAD-box RNA-dependent ATPases are ubiquitous in all domains of life where they bind and remodel RNA and RNA-protein complexes. DEAD-box ATPases with helicase activity unwind RNA duplexes by local opening of helical regions without directional movement through the duplexes and some of these enzymes, including Ded1p from Saccharomyces cerevisiae, oligomerize to effectively unwind RNA duplexes. Whether and how DEAD-box helicases coordinate oligomerization and unwinding is not known and it is unclear how many base pairs are actively opened.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, China.
Frustrated Lewis pair chemistry (FLP) occupy a crucial position in nonmetal-mediated catalysis, especially toward activation of inert gas molecules. Yet, one formidable issue of homogeneous FLP catalysts is their instability on preservation and recycling. Here we contribute a general solution that marries the polyhedral oligomeric silsesquioxane (POSS) with a structurally specific frustrated Lewis acid to fabricate porous polymer networks, which can form water-insensitive heterogeneous FLP catalysts upon employing Lewis base substrates.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Winogradsky Institute of Microbiology, Research Center of Biotechnology, Russian Academy of Sciences, 119071 Moscow, Russia.
The Dps protein is the major DNA-binding protein of prokaryotes, which protects DNA during starvation by forming a crystalline complex. The structure of such an intracellular DNA-Dps complex is still unknown. However, the phenomenon of a decrease in the size of the Dps protein from 90 Å to 69-75 Å during the formation of a complex with DNA has been repeatedly observed, and no explanation has been given.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
A. N. Belozersky Institute of Physico-Chemical Biology, M. V. Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, Moscow 119992, Russia.
Artificial peptides P4, A1 and A4 are homologous to amphipathic α-helical fragments of the influenza virus M1 protein. P4 and A4 contain the cholesterol recognition sequence CARC, which is absent in A1. As shown previously, P4 and A4 but not A1 have cytotoxic effects on some eukaryotic and bacterial cells.
View Article and Find Full Text PDFBiomolecules
December 2024
Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, 157 01 Athens, Greece.
Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by extracellular amyloid plaques, predominantly consisting of amyloid- (A) peptides. The oligomeric form of A is acknowledged as the most neurotoxic, propelling the pathological progression of AD. Interestingly, besides A, other proteins are co-localized within amyloid plaques.
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