Disproportionate presence of adenosine in mitochondrial and chloroplast DNA of Chlamydomonas reinhardtii

• Published in: iScience 2021-01, Vol.24 (1), p.102005-102005, Article 102005
• Main Authors: El-Sayed, Waleed M.M., Gombolay, Alli L., Xu, Penghao, Yang, Taehwan, Jeon, Youngkyu, Balachander, Sathya, Newnam, Gary, Tao, Sijia, Bowen, Nicole E., Brůna, Tomáš, Borodovsky, Mark, Schinazi, Raymond F., Kim, Baek, Chen, Yongsheng, Storici, Francesca
• Format: Article
• Language: English
• Subjects: Genomics; Molecular Biology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2020.102005

Ribonucleoside monophosphates (rNMPs) represent the most common non-standard nucleotides found in the genome of cells. The distribution of rNMPs in DNA has been studied only in limited genomes. Using the ribose-seq protocol and the Ribose-Map bioinformatics toolkit, we reveal the distribution of rNMPs incorporated into the whole genome of a photosynthetic unicellular green alga, Chlamydomonas reinhardtii. We discovered a disproportionate incorporation of adenosine in the mitochondrial and chloroplast DNA, in contrast to the nuclear DNA, relative to the corresponding nucleotide content of these C. reinhardtii organelle genomes. Our results demonstrate that the rNMP content in the DNA of the algal organelles reflects an elevated ATP level present in the algal cells. We reveal specific biases and patterns in rNMP distributions in the algal mitochondrial, chloroplast, and nuclear DNA. Moreover, we identified the C. reinhardtii orthologous genes for all three subunits of the RNase H2 enzyme using GeneMark-EP + gene finder. [Display omitted] •The sites of ribonucleotides embedded in Chlamydomonas reinhardtii DNA are revealed•Adenosine is disproportionally abundant in algal mitochondrial and chloroplast DNA•There is a high ATP level present in the algal cells•C. reinhardtii orthologous genes for the three subunits of ribonuclease H2 are found Molecular Biology; Genomics