Three Binding Sites of ABCE1 (IMAGE) Goethe University Frankfurt Caption Three states of nucleotide binding sites can be seen in the histogram: open, intermediate and closed. Credit T. Cordes, LMU Munich 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.