Credit: Los Alamos National Laboratory
An example of RNA folded into a tetraloop, in this case the “Z-form duplex” under study that could provide medical treatment opportunities for retroviral diseases such as Zika and Ebola. RNA nucleobases are colored using this key (Gray: Guanosine, Green: Cytosine, White: Adenosine). Hydrogen bonds are shown in blue. The sequence is gcGCAAgc (capitals indicate residues forming the loop).