TY - JOUR
T1 - Structural basis of the redox switches in the NAD+-reducing soluble [NiFe]-hydrogenase
AU - Shomura, Y.
AU - Taketa, M.
AU - Nakashima, H.
AU - Tai, H.
AU - Nakagawa, H.
AU - Ikeda, Y.
AU - Ishii, M.
AU - Igarashi, Y.
AU - Nishihara, H.
AU - Yoon, K. S.
AU - Ogo, S.
AU - Hirota, S.
AU - Higuchi, Y.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - NAD+ (oxidized form of NAD: nicotinamide adenine dinucleotide)-reducing soluble [NiFe]-hydrogenase (SH) is phylogenetically related to NADH (reduced form of NAD+):quinone oxidoreductase (complex I), but the geometrical arrangements of the subunits and Fe-S clusters are unclear. Here, we describe the crystal structures of SH in the oxidized and reduced states. The cluster arrangement is similar to that of complex I, but the subunits orientation is not, which supports the hypothesis that subunits evolved as prebuilt modules. The oxidized active site includes a six-coordinate Ni, which is unprecedented for hydrogenases, whose coordination geometry would prevent O2 from approaching. In the reduced state showing the normal active site structure without a physiological electron acceptor, the flavin mononucleotide cofactor is dissociated, which may be caused by the oxidation state change of nearby Fe-S clusters and may suppress production of reactive oxygen species.
AB - NAD+ (oxidized form of NAD: nicotinamide adenine dinucleotide)-reducing soluble [NiFe]-hydrogenase (SH) is phylogenetically related to NADH (reduced form of NAD+):quinone oxidoreductase (complex I), but the geometrical arrangements of the subunits and Fe-S clusters are unclear. Here, we describe the crystal structures of SH in the oxidized and reduced states. The cluster arrangement is similar to that of complex I, but the subunits orientation is not, which supports the hypothesis that subunits evolved as prebuilt modules. The oxidized active site includes a six-coordinate Ni, which is unprecedented for hydrogenases, whose coordination geometry would prevent O2 from approaching. In the reduced state showing the normal active site structure without a physiological electron acceptor, the flavin mononucleotide cofactor is dissociated, which may be caused by the oxidation state change of nearby Fe-S clusters and may suppress production of reactive oxygen species.
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U2 - 10.1126/science.aan4497
DO - 10.1126/science.aan4497
M3 - Article
C2 - 28860386
AN - SCOPUS:85029514393
VL - 357
SP - 928
EP - 932
JO - Science
JF - Science
SN - 0036-8075
IS - 6354
ER -