98%
921
2 minutes
20
Convergent evolutionary events in independent lineages provide an opportunity to understand why evolution favors certain outcomes over others. We studied such a case where a large set of genes-those coding for the ribosomal proteins-gained -regulatory sequences for a particular transcription regulator (Mcm1) in independent fungal lineages. We present evidence that these gains occurred because Mcm1 shares a mechanism of transcriptional activation with an ancestral regulator of the ribosomal protein genes, Rap1. Specifically, we show that Mcm1 and Rap1 have the inherent ability to cooperatively activate transcription through contacts with the general transcription factor TFIID. Because the two regulatory proteins share a common interaction partner, the presence of one ancestral -regulatory sequence can 'channel' random mutations into functional sites for the second regulator. At a genomic scale, this type of intrinsic cooperativity can account for a pattern of parallel evolution involving the fixation of hundreds of substitutions.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6173580 | PMC |
http://dx.doi.org/10.7554/eLife.37563 | DOI Listing |
Inorg Chem
September 2025
Laboratoire de Chimie Physique Matière et Rayonnement (LCPMR), CNRS UMR 7614, Sorbonne Université (SU), 4 place Jussieu, Paris 75005, France.
The one-photon KV X-ray photoelectron spectra of Na and its hydrated clusters [Na(HO)] ( = 1-6) are dominated by the unusual 1s → 1s3s transition. KV spectroscopy also reveals a pronounced redistribution of the 1s → 1s3p transition cross sections, directly correlated with hydration number and molecular arrangement. Its intrinsic two-step nature, involving simultaneous core ionization and core excitation, enables detailed investigation of solvation-induced electronic structure changes, including dipole-forbidden excitations, core-valence charge transfer, and subtle 1s → V energy shifts.
View Article and Find Full Text PDFAdv Mater
September 2025
Research Center for Crystal Materials, CAS Key Laboratory of Functional Materials and Devices for Special Environmental Conditions, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, 830011, P. R. China.
The generation of coherent deep-ultraviolet (DUV) radiation via nonlinear frequency conversion remains a major scientific and technological challenge in modern optics. To date, only a very limited number of nonlinear optical (NLO) crystals-such as KBBF, ABF, and quartz-have been experimentally demonstrated to support measurable direct second-harmonic generation (SHG) at wavelengths of 177 nm or shorter. There is a pressing need to develop alternative materials or strategies that enable efficient frequency conversion in the DUV region.
View Article and Find Full Text PDFAnal Biochem
September 2025
Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-Cho Minami, Tottori, 680-8552, Japan.
The duplex-forming behavior of an inchworm-type PNA-PEG conjugate (i-PPc), engineered for the selective recognition of point mutations in DNA, was assessed through thermodynamic analysis employing UV melting curves and circular dichroism spectroscopy. The i-PPc demonstrated the ability to form stable duplexes exclusively with fully complementary DNA sequences, while no hybridization with single-base mismatched sequences. This binary on/off hybridization behavior was maintained even under physiologically relevant conditions (37 °C), thereby illustrating the exceptional point mutation discrimination capability of i-PPc.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1RX, UK.
Porous metal-organic polyhedra (MOPs) have strong covalent and coordinate bonds that define the intrinsic pore of the cage. The intermolecular interactions between cages tend to be weaker, such that they rearrange during the solvent exchange process preceding gas sorption measurements. The reduction in crystal size that this often causes limits the availability of structural data that could enable understanding of observed gas uptake.
View Article and Find Full Text PDFAcc Chem Res
September 2025
Department of Pharmaceutical Chemistry and Small Molecule Discovery Center, University of California, San Francisco 94158, United States.
ConspectusProtein-protein interactions (PPIs) play a key role in homeostasis and are often dysregulated in disease. PPIs were traditionally considered "undruggable" due to their flat surfaces and disordered domains. Recently, the identification of PPI stabilizers, or molecular glues (MGs), compounds that bind cooperatively to PPI interfaces, has provided a new direction for the field.
View Article and Find Full Text PDF