Three-dimensional structure of recombinant human interferon-gamma.

Science (New York, N.Y.) (1991-05-03)
S E Ealick, W J Cook, S Vijay-Kumar, M Carson, T L Nagabhushan, P P Trotta, C E Bugg

The x-ray crystal structure of recombinant human interferon-gamma has been determined with the use of multiple-isomorphous-replacement techniques. Interferon-gamma, which is dimeric in solution, crystallizes with two dimers related by a noncrystallographic twofold axis in the asymmetric unit. The protein is primarily alpha helical, with six helices in each subunit that comprise approximately 62 percent of the structure; there is no beta sheet. The dimeric structure of human interferon-gamma is stabilized by the intertwining of helices across the subunit interface with multiple intersubunit interactions.