A third purine biosynthetic pathway encoded by aminoadenine-based viral DNA genomes

• DOI: 10.1126/science.abe6494
• Publication Date: 2021-04-29T19:05:18Z
• Authors: Dona Sleiman; Pierre Simon Garcia; Marion Lagune; Jerome Loc’h; Ahmed Haouz; Najwa Taib; Pascal Röthlisberger; Simonetta Gribaldo; Philippe Marlière; Pierre Alexandre ...
• Keywords: 0301 basic medicine; 570; Molecular Biology/Biochemistry [q-bio.BM]; Genome, Viral; Viral Nonstructural Proteins; Crystallography, X-Ray; [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry; Adenylosuccinate Synthase; 03 medical and health sciences; MESH: 2-Aminopurine; MESH: Genome; MESH: Adenylosuccinate Synthase; Bacteriophages; Viral; MESH: Bacteriophages; [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM]; MESH: Phylogeny; 2-Aminopurine; Phylogeny; 2. Zero hunger; [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM]; Molecular Biology/Structural Biology [q-bio.BM]; MESH: Crystallography; MESH: DNA; MESH: Crystallography, X-Ray; MESH: DNA, Viral; Biosynthetic Pathways; 3. Good health; [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry; DNA, Viral; X-Ray; MESH: Viral Nonstructural Proteins; MESH: Biosynthetic Pathways; MESH: Genome, Viral

Biosynthesis and replication, from A to Z

Four nucleobases. adenine (A), cytosine (C), guanine (G), and thymine (T), are usually thought to be invariable in DNA. In bacterial viruses, however, each of the DNA bases have variations that help them to escape degradation by bacterial restriction enzymes. In the genome of cyanophage S-2L, A is completely replaced by diaminopurine (Z), which forms three hydrogen bonds with T and thus creates non–Watson-Crick base pairing in the DNA of this virus (see the Perspective by Grome and Isaacs). Zhou et al. and Sleiman et al. determined the biochemical pathway that produces Z, which revealed more Z genomes in viruses hosted in bacteria distributed widely in the environment and phylogeny. Pezo et al. identified a DNA polymerase that incorporates Z into DNA while rejecting A. These findings enrich our understanding of biodiversity and expand the genetic palette for synthetic biology.

Science , this issue p. 512 , 516 , 520 ; see also p. 460