Prebiotic nucleotide synthesis is crucial to understanding the origins of life on Earth. There are numerous candidates for life's first nucleic acid, however, currently no prebiotic method to selectively and concurrently synthesise the canonical Watson-Crick base-pairing pyrimidine (C, U) and purine (A, G) nucleosides exists for any genetic polymer. Here, we demonstrate the divergent prebiotic synthesis of arabinonucleic acid (ANA) nucleosides. The complete set of canonical nucleosides is delivered from one reaction sequence, with regiospecific glycosidation and complete furanosyl selectivity. We observe photochemical 8-mercaptopurine reduction is efficient for the canonical purines (A, G), but not the non-canonical purine inosine (I). Our results demonstrate that synthesis of ANA may have been facile under conditions that comply with plausible geochemical environments on early Earth and, given that ANA is capable of encoding RNA/DNA compatible information and evolving to yield catalytic ANA-zymes, ANA may have played a critical role during the origins of life.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6172253 | PMC |
http://dx.doi.org/10.1038/s41467-018-06374-z | DOI Listing |
Comput Biol Chem
December 2024
Faculty of Biochemistry and Molecular Medicine, University of Oulu, PO Box 5400, Oulu 90014, Finland; Biocenter Oulu, University of Oulu, PO Box 5400, Oulu 90014, Finland. Electronic address:
Single-stranded breaks (SSBs) are the most frequent DNA lesions threatening genomic integrity-understanding how DNA sensor proteins recognize certain SSB types is crucial for studies of the DNA repair pathways. During repair of damaged DNA the final SSB that is to be ligated contains a 5'-phosphorylated end. The present work employed molecular simulation (MD) of DNA with a phosphorylated break in solution to address multiple questions regarding the dynamics of the break site.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
Cross-feeding involves microbes consuming exudates of other surrounding microbes, mediating elemental cycling. Characterizing the diversity of cross-feeding pathways in ocean microbes illuminates evolutionary forces driving self-organization of ocean ecosystems. Here, we uncover a purine and pyrimidine cross-feeding network in globally abundant groups.
View Article and Find Full Text PDFJ Int AIDS Soc
January 2025
Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Introduction: Long-acting injectable cabotegravir (CAB-LA) for pre-exposure prophylaxis significantly reduced HIV acquisition in HPTN 084. We report on the safety and CAB-LA pharmacokinetics in pregnant women during the blinded period of HPTN 084.
Methods: Participants were randomized 1:1 to either active cabotegravir (CAB) plus tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) placebo or active TDF/FTC plus CAB placebo.
Front Pharmacol
December 2024
School of Basic Medicine, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou, China.
Introduction: The mechanism of tannic acid (TA) intervention on methicillin-resistant (MRSA, USA 300) biofilm formation was explored using proteomics.
Methods: The minimum inhibitory concentration (MIC) of TA against the MRSA standard strain USA 300 was determined by two-fold serial dilution of the microbroth. The effects of TA were studied using crystal violet staining.
J Acquir Immune Defic Syndr
October 2024
Harvard TH Chan School of Public Health, Boston, MA, USA.
Introduction: Women with HIV (WHIV) have higher risks of adverse pregnancy outcomes, particularly in the absence of antiretroviral treatment(ART), and timing of ART may impact risk.
Methods: In IMPAACT 2010 (VESTED), 643 pregnant WHIV in 9 countries were randomized 1:1:1 to initiate ART: dolutegravir (DTG)+emtricitabine(FTC)/tenofovir alafenamide(TAF); DTG+FTC/tenofovir disoproxil fumarate (TDF) or efavirenz (EFV)/FTC/TDF. We describe adverse pregnancy outcomes in women with a subsequent pregnancy during 50 weeks of postpartum follow-up: spontaneous abortion (<20 weeks), stillbirth (≥20 weeks), preterm delivery (<37 weeks) and small-for-gestational-age (SGA).
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!