New studies suggest Z-genome is much more widespread in bacteria-invading viruses than thought

Three teams working independently found evidence that the Z-genome in bacteriophages is much more widespread than previously thought.

The genomic DNA of most living things has four distinct nucleotides: adenine, thymine, cytosine and guanine, respectively labeled ATCG. But back in 1977, scientists learned that most bacteriophages have a slightly different alphabet, one that typically omits adenine and adds diaminopurine, which has subsequently been labeled Z. After this discovery, it was thought that the alphabet was so rare little work was done to learn more about it; thus, little is known about how bacteriophages function without adenine in their genome. In this new effort, all three teams sought to learn more about the Z nucleotide and how it works in bacteriophages.

https://phys.org/news/2021-04-z-genome-widespread-bacteria-invading-viruses-thought.html