Indoleamine 2,3-dioxygenase 1 has sparked interest as an immunotherapeutic target in cancer research. Its structure includes a loop, named the JK-loop, that controls the orientation of the substrate or inhibitor within the active site. However, little has been reported about the crystal structure of this loop. In the present work, the conformation of the JK-loop is determined for the first time in the presence of the heme cofactor in the active site through X-ray diffraction experiments (2.44 Å resolution). Molecular-dynamics trajectories were also obtained to provide dynamic information about the loop according to the presence of cofactor. This new structural and dynamic information highlights the importance of the JK-loop in confining the labile heme cofactor to the active site.
Colchicine Synergism of Mouse Hair Root Changes Produced by X-ray Irradiation11From the Department of Medicine (Section of Dermatology), Department of Radiology and Argonne Cancer Research Hospital, University of Chicago, Chicago 37, Illinois.This work was supported in part by Public Health Service Grant No. E-1444(C5).Presented at the twenty-second Annual Meeting of The Society for Investigative Dermatology, Inc., New York, N.Y., June 27, 1961.