2SBL

The three-dimensional structure of an arachidonic acid 15-lipoxygenase.

(1993) Science 260: 1482-1486

• PubMed: 8502991 Search on PubMed
• DOI: https://doi.org/10.1126/science.8502991
• Primary Citation of Related Structures:  
  2SBL


• PubMed Abstract: 
  

  In mammals, the hydroperoxidation of arachidonic acid by lipoxygenases leads to the formation of leukotrienes and lipoxins, compounds that mediate inflammatory responses. Lipoxygenases are dioxygenases that contain a nonheme iron and are present in many animal cells. Soybean lipoxygenase-1 is a single-chain, 839-residue protein closely related to mammalian lipoxygenases. The structure of soybean lipoxygenase-1 solved to 2.6 angstrom resolution shows that the enzyme has two domains: a 146-residue beta barrel and a 693-residue helical bundle. The iron atom is in the center of the larger domain and is coordinated by three histidines and the COO- of the carboxyl terminus. The coordination geometry is nonregular and appears to be a distorted octahedron in which two adjacent positions are not occupied by ligands. Two cavities, in the shapes of a bent cylinder and a frustum, connect the unoccupied positions to the surface of the enzyme. The iron, with two adjacent and unoccupied positions, is poised to interact with the 1,4-diene system of the substrate and with molecular oxygen during catalysis.

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Organizational Affiliation: 

Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205.