TY  - JOUR
A1  - Hahn, Aaron
A1  - Engelhard, Christopher
A1  - Reschke, Stefan
A1  - Teutloff, Christian
A1  - Bittl, Robert
A1  - Leimkühler, Silke
A1  - Risse, Thomas
T1  - Structural Insights into the Incorporation of the Mo Cofactor into Sulfite Oxidase from Site-Directed Spin Labeling
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
N2  - Mononuclear molybdoenzymes catalyze a broad range of redox reactions and are highly conserved in all kingdoms of life. This study addresses the question of how the Mo cofactor (Moco) is incorporated into the apo form of human sulfite oxidase (hSO) by using site-directed spin labeling to determine intramolecular distances in the nanometer range. Comparative measurements of the holo and apo forms of hSO enabled the localization of the corresponding structural changes, which are localized to a short loop (residues 263-273) of the Moco-containing domain. A flap-like movement of the loop provides access to the Moco binding-pocket in the apo form of the protein and explains the earlier studies on the in vitro reconstitution of apo-hSO with Moco. Remarkably, the loop motif can be found in a variety of structurally similar molybdoenzymes among various organisms, thus suggesting a common mechanism of Moco incorporation.
KW  - biocatalysis
KW  - cofactors
KW  - enzymes
KW  - EPR spectroscopy
KW  - protein structures
Y1  - 2015
U6  - https://doi.org/10.1002/anie.201504772
SN  - 1433-7851
SN  - 1521-3773
VL  - 54
IS  - 40
SP  - 11865
EP  - 11869
PB  - Wiley-VCH
CY  - Weinheim
ER  -