The minichromosome maintenance (MCM) complex is the replicative helicase responsible for unwinding DNA during archaeal and eukaryal genome replication. To mimic long helicase events in the cell, a high-temperature single-molecule assay was designed to quantitatively measure long-range DNA unwinding of individual DNA helicases from the archaeons Methanothermobacter thermautotrophicus (Mth) and Thermococcus sp. 9°N (9°N). Mth encodes a single MCM homolog while 9°N encodes three helicases. 9°N MCM3, the proposed replicative helicase, unwinds DNA at a faster rate compared to 9°N MCM2 and to Mth MCM. However, all three MCM proteins have similar processivities. The implications of these observations for DNA replication in archaea and the differences and similarities among helicases from different microorganisms are discussed. Development of the high-temperature single-molecule assay establishes a system to comprehensively study thermophilic replisomes and evolutionary links between archaeal, eukaryal, and bacterial replication systems.
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http://dx.doi.org/10.1093/nar/gkw612 | DOI Listing |
Animals (Basel)
January 2025
Joint International Research Laboratory of Animal Health and Food Safety of Ministry of Education, Single Molecule Biochemistry & Biomedicine Laboratory (Sinmolab), College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Porcine epidemic diarrhea virus (PEDV) continues to spread globally, causing clinical symptoms in piglets, including watery diarrhea, vomiting, and dehydration. Its exceptionally high morbidity and mortality rate contributes significantly to the economic losses of the swine industry. The continuous genetic mutations of PEDV have compromised the effectiveness of classical strain vaccines.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
Searching for single-molecule magnets (SMM) with large effective blocking barriers, long relaxation times, and high magnetic blocking temperatures is vitally important not only for the fundamental research of magnetism at the molecular level but also for the realization of new-generation magnetic memory unit. Actinides (An) atoms possess extremely strong spin-orbit coupling (SOC) due to their 5 orbitals, and their ground multiplets are largely split into several sublevels because of the strong interplay between the SOC of An atoms and the crystal field (CF) formed by ligand atoms. Compared to TM-based SMMs, more dispersed energy level widths of An-based SMMs will give a larger total zero field splitting (ZFS) and thus provide a necessary condition to derive a higher .
View Article and Find Full Text PDFSmall
January 2025
Key Laboratory of Chemical Additives for China National Light Industry, College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, P. R. China.
Regulating strategies for long persistent luminescence (LPL) are always in high demand. Herein, a series of coordination polymers (CPs) (SUST-Z1-Z4) are fabricated using 1,10-phenanthroline derivatives involving different substituents (─H, ─CH, ─Cl, and ─Br) as ligands, respectively. Crystallographic data demonstrate that these CPs adopt alternating arrangements of cadmium halide chains and π-conjugated ligands.
View Article and Find Full Text PDFChem Asian J
January 2025
Department of Chemistry, Indian Institute of Technology, Bombay, Powai, 400076, Mumbai, India.
Isostructural Dy(III) and Er(III) complexes [L Ln(HO)][I] ⋅ L ⋅ (CHCl) (Ln=Dy (1), Er (3)) and [L Ln(HO)][I] ⋅ L ⋅ (CHCl) (Ln=Dy (2), Er (4)), with distorted pentagonal bipyramidal geometry (D) around the central metal were synthesized by utilizing two bulky phosphonamide ligands, adamantyl phosphonamide, (Ad)P(O)(NHPr) (L) and carbazolyl phosphoramide (Cz)P(O)(NHPr) (L). The resultant complexes were investigated for their magnetic properties in order to elucidate the impact of modification of the coordinating P-O bond environment either by increasing steric bulk and/or introduction of a third P-N bond at the central phosphorus atom. Magnetic studies revealed substantial energy barriers (U) of 640 K and 491 K for Dy compounds 1 and 2, respectively, rendering them as some of the best-performing air-stable SIMs amongst the class of SIMs with D symmetry.
View Article and Find Full Text PDFACS Sens
January 2025
School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China.
Background noise interferes with the accurate detection of early tumor biomarkers. This study introduces a method that effectively reduces background noise to enhance detection accuracy by combining a color-coded signaling approach with the unique fluorescent properties and room-temperature tunable quantum spin characteristics of fluorescent diamonds (FNDs) with nitrogen-vacancy centers. In this approach, a red signal indicates the presence of the target analyte within the spectral region, a green signal indicates its absence, and a yellow signal indicates the need for further analysis using FNDs' quantum spin properties for optical detection magnetic resonance (ODMR) to distinguish the FND signal from background noise.
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