The angiotensin II AT1A receptor belongs to the G-protein coupled receptors (GPCRs). Like other membrane proteins, GPCRs are not easily amenable to direct structure determination by the currently available methods. The peptide encompassing the putative first extracellular loop of AT1A (residues Thr88-Leu100, el1) has been synthesized along with a cyclic model where the linear peptide has been covalently linked to a template designed to keep the distance between the peptide termini as expected in the receptor. The conformational features of the two molecules have been studied using circular dichroism and NMR techniques. The region W94PFG97 forms a type-II beta-turn and undergoes a Trp-Pro peptide bond cis-trans isomerization in both peptides confirming that these characteristics are intrinsic to el1. In addition, the presence of the spacer seems to modulate the flexibility of the peptide.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/psc.449 | DOI Listing |
The proximity ligation-based Hi-C and derivative methods are the mainstream tools to study genome-wide chromatin interactions. These methods often fragment the genome using enzymes functionally irrelevant to the interactions per se, restraining the efficiency in identifying structural features and the underlying regulatory elements. Here we present Footprint-C, which yields high-resolution chromatin contact maps built upon intact and genuine footprints protected by transcription factor (TF) binding.
View Article and Find Full Text PDFNat Commun
December 2024
Architecture and Dynamics of Biological Macromolecules, Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Paris, France.
Replication Protein A (RPA) plays a pivotal role in DNA replication by coating and protecting exposed single-stranded DNA, and acting as a molecular hub that recruits additional replication factors. We demonstrate that archaeal RPA hosts a winged-helix domain (WH) that interacts with two key actors of the replisome: the DNA primase (PriSL) and the replicative DNA polymerase (PolD). Using an integrative structural biology approach, combining nuclear magnetic resonance, X-ray crystallography and cryo-electron microscopy, we unveil how RPA interacts with PriSL and PolD through two distinct surfaces of the WH domain: an evolutionarily conserved interface and a novel binding site.
View Article and Find Full Text PDFNat Commun
December 2024
Laboratory of Retrovirology, The Rockefeller University, New York, NY, 10065, USA.
ZAP is an antiviral protein that binds to and depletes viral RNA, which is often distinguished from vertebrate host RNA by its elevated CpG content. Two ZAP cofactors, TRIM25 and KHNYN, have activities that are poorly understood. Here, we show that functional interactions between ZAP, TRIM25 and KHNYN involve multiple domains of each protein, and that the ability of TRIM25 to multimerize via its RING domain augments ZAP activity and specificity.
View Article and Find Full Text PDFNat Commun
December 2024
Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China.
By targeting the essential viral RNA-dependent RNA polymerase (RdRP), nucleoside analogs (NAs) have exhibited great potential in antiviral therapy for RNA virus-related diseases. However, most ribose-modified NAs do not present broad-spectrum features, likely due to differences in ribose-RdRP interactions across virus families. Here, we show that HNC-1664, an adenosine analog with modifications both in ribose and base, has broad-spectrum antiviral activity against positive-strand coronaviruses and negative-strand arenaviruses.
View Article and Find Full Text PDFNat Commun
December 2024
Beijing Frontier Research Center for Biological Structure, State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
Exceptionally diverse type V CRISPR-Cas systems provide numerous RNA-guided nucleases as powerful tools for DNA manipulation. Two known Cas12e nucleases, DpbCas12e and PlmCas12e, are both effective in genome editing. However, many differences exist in their in vitro dsDNA cleavage activities, reflecting the diversity in Cas12e's enzymatic properties.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!