In the world of microbial warfare, sometimes you have to change your own structure of who you are.
Bacterial viruses, appropriately called bacteria, and their victims have been at war for many years, each developing increasingly nefarious tactics to infect or destroy that. each other Some bacteria eventually took the arms race to a whole new level by changing the way their DNA is coded.
At least that’s what we think happened. When thought to be unusual, new research published in three separate papers shows a large number of bacteria with unstandard DNA that researchers call the Z-genome.
“The DNA of the genome is made up of four standard nucleotides … these nucleobases form the ATCG genetic alphabet, which is preserved in all the domains of life,”; says biologist Michael Grome and Farren Isaacs. Write on science Editorial accompanying new research on bacterial genetics
“However, in the year. In 1977, DNA of the cyanophage virus S-2L was discovered, with all cases of ‘A’ being replaced. 2-aminoadenine (Z) throughout the genome forming the ZTCG genetic alphabet.
As it appears to be self-defense within the interconnected ‘rungs’ of the DNA double helix, the base ‘Z’ base DNA forms a triple bond equal to the opposite ‘T’ base, one of the more than two bonds of a normal A: T connection. This makes the virus genome harder and bacteria more difficult to separate from chemicals known as nucleases.
Although the scientists were amazed But no other bacteria with the Z genome were found, and with the difficulty of culturing S-2L in the laboratory, the Z genome was placed out of curiosity.
Now, the work recorded in three separate studies from researchers in France and China shows that this is not a one-off, while simultaneously explaining the nature of the Z-genome and how it is assembled.
“Scientists have long dreamed of diversifying bases. Our work shows that nature has figured out how to do so,” said one of the team led by Yan Zhou, the first author from Tianjin University. Write them in their papers
Zhou’s team, along with another group led by Institut Pasteur microbiologist Dona Sleiman, found two main proteins they call PurZ and PurB; These make up the base ‘Z’.
A third group, led by Université Paris-Saclay synthetic biologist Valerie Pezo, confirmed those findings and analyzed an enzyme called DpoZ, which is responsible for the entire Z-genome together.
All three searched genetic sequencing databases for sequences related to their proteins and enzymes and found a wide variety of bacteria with similar genes.
“[The authors] Has done an amazingly comprehensive job of showing that this is not a crazy unusual thing. But there is an entire group of bacteria carrying this type of genetic material, ”said Jef Boeke, a molecular biologist at New York University who was not involved in the work. Scientist.
There are still many questions to be answered about the Z-genome.
For example, is the Z-genome compatible with normal cell machines like ours? And can it be used in the same way that artificial DNA began?
“The Z base is clearly identified in the carbonaceous meteorite and is proposed as a nucleobase capable of determining the origin of life,” Zhou lead the team wrote in the paper.
“Considering that the base Z was discovered in a meteorite, our work may spark interest in interdisciplinary research into the origins of life and astrology.”
All three papers are published in science Here, here and here