The essential aspects of the ribosome's mechanism can be extracted from coarse-grained simulations, including the ratchet motion, the movement together of critical bases at the decoding center, and movements of the peptide tunnel lining that assist in the expulsion of the synthesized peptide. Because of its large size, coarse graining helps to simplify and to aid in the understanding of its mechanism. Results presented here utilize coarse-grained elastic network modeling to extract the dynamics, and both RNAs and proteins are coarse grained. We review our previous results, showing the well-known ratchet motions and the motions in the peptide tunnel and in the mRNA tunnel. The motions of the lining of the peptide tunnel appear to assist in the expulsion of the growing peptide chain, and clamps at the ends of the mRNA tunnel with three proteins ensure that the mRNA is held tightly during decoding and essential for the helicase activity at the entrance. The entry clamp may also assist in base recognition to ensure proper selection of the incoming tRNA. The overall precision of the ribosome machine-like motions is remarkable.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4789072 | PMC |
http://dx.doi.org/10.1016/j.jmb.2015.12.003 | DOI Listing |
Immunity
December 2024
The Hansjörg Wyss Department of Plastic Surgery, New York University Grossman School of Medicine, New York, NY, USA; Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA. Electronic address:
Hidradenitis suppurativa (HS) is a chronic, debilitating inflammatory skin disease characterized by keratinized epithelial tunnels that grow deeply into the dermis. Here, we examined the immune microenvironment within human HS lesions. Multi-omics profiling and multiplexed imaging identified tertiary lymphoid structures (TLSs) near HS tunnels.
View Article and Find Full Text PDFChemistry
December 2024
Department of Chemical Sciences (DiSC), University of Padova, Via F. Marzolo 1, Padova, 35131, Italy.
This work reports single-crystal X-ray diffraction (XRD), Scanning Tunneling Microscopy (STM), and quantum mechanics calculations of the 3-helical peptide Z-(Aib)-L-Dap(Boc)-Aib-NHiPr (Aib, α-aminoisobutyric acid; Dap, 2,3-diaminopropionic acid; Z, benzyloxycarbonyl; Boc, t-butoxycarbonyl). The peptide forms a double-helical superstructure, studied by XRD and STM. Such architecture is rare in short peptides.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, School of Physics and Astronomy, Zhang Jiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China.
Photolyase and cryptochrome belong to a group of structurally similar flavoproteins but with two distinct functions of DNA repair as a photoenzyme and signal transduction as a photoreceptor, respectively, under blue-light illumination. Here, we studied a recently discovered bifunctional cryptochrome (CraCRY) with focus on its repair of UV-induced pyrimidine-pyrimidone (6-4) photoproduct (6-4PP). We used femtosecond spectroscopy and site-directed mutagenesis to map out the critical elementary steps by following the dynamics of initial reactants, various intermediates, and final products.
View Article and Find Full Text PDFPhysiol Rep
November 2024
Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA.
Proc Natl Acad Sci U S A
November 2024
Center for Epigenomics and Translational Research in Inflammatory Skin Diseases, University of Alabama at Birmingham, Birmingham, AL 35294.
Hidradenitis suppurativa (HS) is a chronic, debilitating inflammatory skin disease with a poorly understood immunopathogenesis. Here, we report that HS lesional skin is characterized by the expansion of innate lymphocytes and T cells expressing CD2, an essential activation receptor and adhesion molecule. Lymphocytes expressing elevated CD2 predominated with unique spatial distribution throughout the epidermis and hypodermis in the HS lesion.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!