Yao Cong / Qinfen Zhang / David Woolford / Thorsten Schweikardt / Htet Khant / Matthew Dougherty / Steven J Ludtke / Wah Chiu / Heinz Decker /
PubMed 要旨
Phenoloxidases (POs) occur in all organisms and are involved in skin and hair coloring in mammals, and initiating melanization in wound healing. Mutation or overexpression of PO can cause albinism or ...Phenoloxidases (POs) occur in all organisms and are involved in skin and hair coloring in mammals, and initiating melanization in wound healing. Mutation or overexpression of PO can cause albinism or melanoma, respectively. SDS can convert inactive PO and the oxygen carrier hemocyanin (Hc) into enzymatically active PO. Here we present single-particle cryo-EM maps at subnanometer resolution and pseudoatomic models of the 24-oligomeric Hc from scorpion Pandinus imperator in resting and SDS-activated states. Our structural analyses led to a plausible mechanism of Hc enzyme PO activation: upon SDS activation, the intrinsically flexible Hc domain I twists away from domains II and III in each subunit, exposing the entrance to the active site; this movement is stabilized by enhanced interhexamer and interdodecamer interactions, particularly in the central linker subunits. This mechanism could be applicable to other type 3 copper proteins, as the active site is highly conserved.
EMDB-5100: 24-meric Scorpion Hemocyanin Resting State cryo-EM Density Map at 6.8 Angstrom Resolution PDB-3ixv: Scorpion Hemocyanin resting state pseudo atomic model built based on cryo-EM density map 手法: EM (単粒子) / 解像度: 6.8 Å
EMDB-5101: 24-meric Scorpion Hemocyanin Activated State cryo-EM Density Map at 8 Angstrom Resolution PDB-3ixw: Scorpion Hemocyanin activated state pseudo atomic model built based on cryo-EM density map 手法: EM (単粒子) / 解像度: 8.0 Å
由来
unidentified (未定義)
androctonus australis (サソリ)
キーワード
OXYGEN BINDING / Hemocyanin / Hc / Phenolxoidase activity / Tyrosinase (Ty) / Catecholoxidase (CO) / Enzyme / SDS / cryo-EM / single particle analysis / Copper / Metal-binding / Oxygen transport / Phosphoprotein / Secreted / Transport