The helical structures of DNA and RNA are investigated experimentally using circular dichroism (CD) spectroscopy. The signs and the shapes of the CD spectra are much different between the right- and left-handed structures as well as between DNA and RNA. The main difference lies in the sign at around 295 nm of the CD spectra: it is positive for the right-handed B-DNA and the left-handed Z-RNA but is negative for the left-handed Z-DNA and the right-handed A-RNA. We calculated the SAC-CI CD spectra of DNA and RNA using the tetramer models, which include both hydrogen-bonding and stacking interactions that are important in both DNA and RNA. The SAC-CI results reproduced the features at around 295 nm of the experimental CD spectra of each DNA and RNA, and elucidated that the strong stacking interaction between the two base pairs is the origin of the negative peaks at 295 nm of the CD spectra for both DNA and RNA. On the basis of these facts, we discuss the similarities and differences between RNA and DNA double-helical structures in the CD spectroscopy based on the ChiraSac methodology.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.jpca.6b08023 | DOI Listing |
Preserving a large number of essential yet highly unstable ribosomal DNA (rDNA) repeats is critical for the germline to perpetuate the genome through generations. Spontaneous rDNA loss must be countered by rDNA copy number (CN) expansion. Germline rDNA CN expansion is best understood in Drosophila melanogaster, which relies on unequal sister chromatid exchange (USCE) initiated by DNA breaks at rDNA.
View Article and Find Full Text PDFMob DNA
January 2025
Department of Biology, La Sierra University, Riverside, CA, USA.
Background: Messenger RNA 3' untranslated regions (3'UTRs) control many aspects of gene expression and determine where the transcript will terminate. The polyadenylation signal (PAS) AAUAAA (AATAAA in DNA) is a key regulator of transcript termination and this hexamer, or a similar sequence, is very frequently found within 30 bp of 3'UTR ends. Short interspersed element (SINE) retrotransposons are found throughout genomes in high copy numbers.
View Article and Find Full Text PDFMicrob Cell Fact
January 2025
Human Microbiology Institute, New York, NY, 10014, USA.
Our previous studies revealed the existence of a Universal Receptive System that regulates interactions between cells and their environment. This system is composed of DNA- and RNA-based Teazeled receptors (TezRs) found on the surface of prokaryotic and eukaryotic cells, as well as integrases and recombinases. In the current study, we aimed to provide further insight into the regulatory role of TezR and its loss in Staphylococcus aureus gene transcription.
View Article and Find Full Text PDFJ Exp Clin Cancer Res
January 2025
School of Medicine, Chinese PLA General Hospital, Nankai University, Beijing, China.
Background: Glioblastoma multiforme (GBM) exhibits a cellular hierarchy with a subpopulation of stem-like cells known as glioblastoma stem cells (GSCs) that drive tumor growth and contribute to treatment resistance. NAD(H) emerges as a crucial factor influencing GSC maintenance through its involvement in diverse biological processes, including mitochondrial fitness and DNA damage repair. However, how GSCs leverage metabolic adaptation to obtain survival advantage remains elusive.
View Article and Find Full Text PDFBMC Mol Cell Biol
January 2025
Epigenetics Programme, Babraham Institute, Cambridge, CB22 3AT, UK.
Background: During the latter stages of their development, mammalian oocytes under dramatic chromatin reconfiguration, transitioning from a non-surrounded nucleolus (NSN) to a surrounded nucleolus (SN) stage, and concomitant transcriptional silencing. Although the NSN-SN transition is known to be essential for developmental competence of the oocyte, less is known about the accompanying molecular changes. Here we examine the changes in the transcriptome and DNA methylation during the NSN to SN transition in mouse oocytes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!