cryo-EM enzyme structure (IMAGE) DOE/Brookhaven National Laboratory Caption Long-sought structure of oil-eating enzyme complex: A high-resolution cryo-EM map of the transmembrane two-protein complex (left) allows researchers to determine the locations of individual amino acids that make up the two proteins (right). AlkG (gray) serves and an electron carrier, transporting electrons from its single iron atom (red sphere) to the two iron atoms (red spheres) at the active site of the AlkB enzyme (colorful ribbon structure). The magenta structure below the active site is the substrate (see close-up views). Credit Brookhaven National Laboratory Usage Restrictions OK for use with stories about this research License Original 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.