The final steps of [FeFe]-hydrogenase maturation.
Proc Natl Acad Sci U S A
; 116(32): 15802-15810, 2019 08 06.
Article
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| MEDLINE
| ID: mdl-31337676
ABSTRACT
The active site (H-cluster) of [FeFe]-hydrogenases is a blueprint for the design of a biologically inspired H2-producing catalyst. The maturation process describes the preassembly and uptake of the unique [2FeH] cluster into apo-hydrogenase, which is to date not fully understood. In this study, we targeted individual amino acids by site-directed mutagenesis in the [FeFe]-hydrogenase CpI of Clostridium pasteurianum to reveal the final steps of H-cluster maturation occurring within apo-hydrogenase. We identified putative key positions for cofactor uptake and the subsequent structural reorganization that stabilizes the [2FeH] cofactor in its functional coordination sphere. Our results suggest that functional integration of the negatively charged [2FeH] precursor requires the positive charges and individual structural features of the 2 basic residues of arginine 449 and lysine 358, which mark the entrance and terminus of the maturation channel, respectively. The results obtained for 5 glycine-to-histidine exchange variants within a flexible loop region provide compelling evidence that the glycine residues function as hinge positions in the refolding process, which closes the secondary ligand sphere of the [2FeH] cofactor and the maturation channel. The conserved structural motifs investigated here shed light on the interplay between the secondary ligand sphere and catalytic cofactor.
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Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Hidrogenasas
/
Hierro
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2019
Tipo del documento:
Article
País de afiliación:
Alemania