Z-State (IMAGE) DOE/Los Alamos National Laboratory Caption Z-state: 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). Credit Los Alamos National Laboratory Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.