DNA metabolism

  • Article
    | Open Access

    The cyanophage S-2L incorporates 2-aminoadenine (Z) instead of adenine into its DNA, which still pairs with thymine forming a triple hydrogen bond. Here, the authors identify a third gene mazZ located between purZ and datZ that is required for 2-aminoadenine biosynthesis and determine the crystal structures of MazZ and PurZ. They further show that co-expression of these three genes in E.coli enables 2-aminoadenine incorporation into the bacterial genome.

    • Dariusz Czernecki
    • , Frédéric Bonhomme
    •  & Marc Delarue
  • Article
    | Open Access

    Different factors protect cells from harmful R-loops, but the way these are formed is still unclear. Authors show here that R-loops form co-transcriptionally by different manners and cells possess specialized mechanisms to prevent them in each case, a major mechanism being independent of replication and another one being linked to replication.

    • Marta San Martin-Alonso
    • , María E. Soler-Oliva
    •  & Andrés Aguilera
  • Article
    | Open Access

    Different proteins localised at telomeres ensure chromosome end stability to prevent double strand-end break recognition. Here the authors provide new insight into how in S. cerevisiae the interaction between Rif2 and Rad50 inhibits MRX functions at telomeres.

    • Florian Roisné-Hamelin
    • , Sabrina Pobiega
    •  & Stéphane Marcand
  • Article
    | Open Access

    The cyanophage S-2L incorporates 2-aminoadenine (Z) instead of adenine (A) in its genome. Here, the authors provide an explanation for the absence of A in S-2L genome by identifying and characterising functionally and structurally both the HD phosphohydrolase (datZ) that specifically cleaves dATP, and the sole DNA primase-polymerase of S-2L, nonspecific of dATP or dZTP.

    • Dariusz Czernecki
    • , Pierre Legrand
    •  & Marc Delarue
  • Article
    | Open Access

    Extracting functional information from 16S rRNA data surveys would provide a valuable tool for large-scale functional ecology. Here, the authors use PICRUSt2 to infer metabolic functions from bacterial marker gene data across the South Pacific Ocean, and compare them with rate data, biomass estimators and predictions based on shotgun metagenomes.

    • Eric J. Raes
    • , Kristen Karsh
    •  & Anya M. Waite
  • Article
    | Open Access

    DNA 5-hydroxymethylcytosine (5hmC) modification is associated with gene transcription and used as a mark of mammalian development. Here the authors report a comprehensive 5hmC tissue map and analysis of 5hmC genomic distributions in 19 human tissues derived from 10 organ systems, thus providing insights into the role of 5hmC in tissue-specific development.

    • Xiao-Long Cui
    • , Ji Nie
    •  & Chuan He
  • Article
    | Open Access

    Extrachromosomal circular DNA made of telomeric repeats have been found to have an effect on telomere maintenance. By combining electron microscopy with a telomere purification procedure the authors identify damage-induced i-loops as a key intermediate in telomere circle formation.

    • Giulia Mazzucco
    • , Armela Huda
    •  & Ylli Doksani
  • Article
    | Open Access

    Despite some well-characterized functions in cancer, the impact of most long non-coding RNAs remains unknown. Here, the authors discover the lncRNA lincNMR which is upregulated in cancer and drives cell proliferation by interacting with YBX1 and controlling nucleotide metabolism.

    • Minakshi Gandhi
    • , Matthias Groß
    •  & Sven Diederichs
  • Article
    | Open Access

    Primed adaptation in the CRISPR-Cas system helps recognition of previously encountered sequence elements and promotes the formation of new memories. Here the authors characterized spacer precursors of type I-E and type I-F CRISPR-Cas system using in vivo models.

    • Anna A. Shiriaeva
    • , Ekaterina Savitskaya
    •  & Ekaterina Semenova
  • Article
    | Open Access

    Ribonucleotide reductase (RNR) catalyzes the de novo synthesis of deoxyribonucleoside diphosphates to provide dNTP precursors for DNA synthesis. Here the authors show that the availability of dNTPs, DNA replication, and cellular proliferation, are modulated by acetylation and deacetylation of RRM2 by KAT7 and Sirt2 respectively.

    • Guo Chen
    • , Yin Luo
    •  & Xingming Deng
  • Article
    | Open Access

    DNA sliding clamps are ring-shaped proteins that encircle DNA and harbour polymerases and other factors that promote processive DNA replication. Here the authors use X-ray crystallography, NMR and MD simulations to propose a model for a PCNA sliding mechanism that relies on short-lived polar interactions.

    • Matteo De March
    • , Nekane Merino
    •  & Alfredo De Biasio
  • Article
    | Open Access

    Type III restriction–modification enzymes consists of two methylation and one or two restriction subunits. Here the authors report the structure of the full EcoP15I complex bound to DNA, which suggests mechanisms for ATP hydrolysis dependent diffusion along DNA and how a dimeric methyltransferase modifies only one DNA strand.

    • Yogesh K. Gupta
    • , Siu-Hong Chan
    •  & Aneel K. Aggarwal
  • Article
    | Open Access

    The ability to contain and destroy synthetically engineered microorganisms is an important consideration with environmental, industrial and intellectual property implications. Here Caliando et al. design and demonstrate a stably integrated CRISPR-based system for targeted DNA destruction.

    • Brian J. Caliando
    •  & Christopher A. Voigt