Endonuclease III (EndoIII), which is ubiquitous in bacteria, Archaea and eukaryotes, plays an important role in excising thymine glycol (Tg) from DNA. Herein, we present evidence that an EndoIII from the hyperthermophilic crenarchaeon Sulfolobus islandicus REY15A (Sis-EndoIII) is capable of removing Tg from DNA at high temperature. Biochemical data show that the optimal temperature and pH of Sis-EndoIII are ca.70 °C and ca.7.0-8.0, respectively. Furthermore, the recombinant Sis-EndoIII retains relative weak activity without a divalent metal ion, and displays maximum activity in the presence of Mg or Ca. Additionally, we first revealed the activation energy (E) of 39.7 ± 4.2 kcal/mol for Sis-EndoIII to remove Tg from dsDNA. As a bifunctional glycosylase, Sis-EndoIII possesses AP lyase activity in addition to glycosylase activity. Additionally, a covalent intermediate is formed between Sis-EndoIII and Tg-containing dsDNA. Mutational studies demonstrate that residues D50, K133 and D151 in Sis-EndoIII are responsible for removal of Tg from dsDNA and K133 and D151 are essential for formation of the covalent intermediate. To our knowledge, it is the first report of Tg excision by crenarchaeal EndoIII, thus augmenting our understanding on archaeal EndoIII function.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.10.143 | DOI Listing |
GM Crops Food
December 2025
School of Life Science, Henan University, Kaifeng, Henan, People's Republic of China.
Malic acid markedly affects watermelon flavor. Reducing the malic acid content can significantly increase the sweetness of watermelon. An effective solution strategy is to reduce watermelon malic acid content through molecular breeding technology.
View Article and Find Full Text PDFTarget Oncol
January 2025
Hematology-Oncology Service, Department of Medicine, Centre hospitalier de l'Université de Montréal (CHUM), 1000, rue Saint-Denis, Montreal, QC, Canada.
Background: BERIL-1 was a randomized phase 2 study that studied paclitaxel with either buparlisib, a pan-class I PIK3 inhibitor, or placebo in patients with recurrent or metastatic (R/M) head and neck squamous cell cancer (HNSCC). Considering the therapeutic paradigm shift with immune checkpoint inhibitors (ICIs) now approved in the first-line setting, we present an updated immunogenomic analysis of patients enrolled in BERIL-1, including patients with immune-infiltrated tumors.
Objective: The objective of this study was to identify biomarkers predictive of treatment efficacy in the context of the post-ICI therapeutic landscape.
Environ Monit Assess
January 2025
School of Energy and Power Engineering, Xihua University, No. 9999 Hongguang Street, Chengdu, 610039, Sichuan Province, China.
Analysis of crop water requirement and its influencing factors are important for optimal allocation of water resources. However, research on variations of climatic factors and their contribution to wheat water requirement in Xinjiang is insufficient. In our study, daily meteorological data during 1961‒2017 in Xinjiang was collected.
View Article and Find Full Text PDFCancer Res
January 2025
Stanford University, Stanford, California, United States.
Radiotherapy is an integral component in the treatment of many types of cancer, with approximately half of cancer patients receiving radiotherapy. Systemic therapy applies pressure that can select for resistant tumor subpopulations, underscoring the importance of understanding how radiation impacts tumor evolution to improve treatment outcomes. We integrated temporal genomic profiling of 120 spatially distinct tumor regions from 20 patients with undifferentiated pleomorphic sarcomas (UPS), longitudinal circulating tumor DNA (ctDNA) analysis, and evolutionary biology computational pipelines to study UPS evolution during tumorigenesis and in response to radiotherapy.
View Article and Find Full Text PDFBackground: This study aimed to evaluate the efficacy of third-generation sequencing (TGS) and a thalassemia (Thal) gene diagnostic kit in identifying Thal gene mutations.
Methods: Blood samples (n = 119) with positive hematology screening results were tested using polymerase chain reaction (PCR)-based methods and TGS on the PacBio-Sequel-II-platform, respectively.
Results: Out of the 119 cases, 106 cases showed fully consistent results between the two methods, with TGS identified HBA1/2 and HBB gene mutations in 82 individuals.
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