DNA Replication Caught in the Act (IMAGE) University of Southern California Caption A ring of six proteins known as a helicase surrounds the DNA strands at a special location known as origin DNA. Each of the six proteins is in distinct color, with origin DNA in the center. Credit Xiaojiang Chen, USC 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.