cytosine6

Cytosine6 is a synthetic nucleobase that is not found in natural DNA or RNA. It is a derivative of cytosine, one of the four standard nucleobases in DNA and RNA. Cytosine6, also known as isocytosine, is a structural isomer of cytosine, meaning it has the same chemical formula but a different arrangement of atoms. This difference in structure leads to altered base-pairing properties compared to natural nucleobases.

In standard Watson-Crick base pairing, cytosine pairs with guanine. Cytosine6, however, can form stable base pairs with guanine and also with adenine. This ability to pair with two different natural bases is a key characteristic that distinguishes it from the standard nucleobases. The altered hydrogen bonding patterns are responsible for this unique pairing behavior.

The incorporation of cytosine6 into synthetic nucleic acid structures, such as DNA or RNA analogs, is of interest in the field of synthetic biology and nucleic acid chemistry. These modified nucleic acids, sometimes referred to as xeno nucleic acids (XNA), can exhibit novel properties that may have applications in areas like diagnostics, therapeutics, or information storage. Research into cytosine6 and other unnatural base pairs aims to expand the chemical repertoire of genetic material and explore new functionalities. The stability and fidelity of replication and transcription of such modified systems are ongoing areas of investigation.