6l8s

High resolution crystal structure of crustacean hemocyanin.

spinqualitylabelsall models 6l8s, resolution 1.58Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.58Å Ligands: CL, CU, EDO, MG, NAG, O, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Hemocyanin (Hc) and phenoloxidase (PO) are the members of type 3 copper protein family. Although arthropod Hc and PO exhibit similar three-dimensional structures of the copper-containing active site, Hc functions as an oxygen transport protein, showing minimal or no phenoloxidase activity. Here, we present the crystal structure of the oxy form of Hc from Panulirus japonicus (PjHc) at 1.58A resolution. The structure of the di-copper active site of PjHc was found to be almost identical to that of PO. Although conserved amino acids and the water molecule crucial for the enzymatic activity were observed in PjHc at almost the same positions as those in PO, PjHc showed no enzymatic activity under our experimental conditions. One striking difference between PjHc and arthropod PO was the presence of a "blocker residue" near the binuclear copper site of PjHc. This blocker residue comprised a phenylalanine residue tightly stacked with an imidazole ring of a CuA coordinated histidine and hindered substrates from accessing the active site. Our results suggest that the blocker residue is also a determining factor of the catalytic activity of type 3 copper proteins. The high-resolution crystal structure of lobster hemocyanin shows its enzymatic capability as a phenoloxidase.,Masuda T, Baba S, Matsuo K, Ito S, Mikami B Arch Biochem Biophys. 2020 May 4:108370. doi: 10.1016/j.abb.2020.108370. PMID:32380017 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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