Oxygen-tolerant [NiFe]-hydrogenases: the individual and collective importance of supernumerary cysteines at the proximal Fe-S cluster

Lukey, M. J., Roessler, M. M., Parkin, A., Evans, R. M., Davies, R. A., Lenz, O., Friedrich, B., Sargent, F., Armstrong, F. A. (October 2011) Oxygen-tolerant [NiFe]-hydrogenases: the individual and collective importance of supernumerary cysteines at the proximal Fe-S cluster. J Am Chem Soc, 133 (42). pp. 16881-92. ISSN 1520-5126

Abstract

An important clue to the mechanism for O(2) tolerance of certain [NiFe]-hydrogenases is the conserved presence of a modified environment around the iron-sulfur cluster that is proximal to the active site. The O(2)-tolerant enzymes contain two cysteines, located at opposite ends of this cluster, which are glycines in their O(2)-sensitive counterparts. The strong correlation highlights special importance for electron-transfer activity in the protection mechanism used to combat O(2). Site-directed mutagenesis has been carried out on Escherichia coli hydrogenase-1 to substitute these cysteines (C19 and C120) individually and collectively for glycines, and the effects of each replacement have been determined using protein film electrochemistry and electron paramagnetic resonance (EPR) spectroscopy. The "split" iron-sulfur cluster EPR signal thus far observed when oxygen-tolerant [NiFe]-hydrogenases are subjected to oxidizing potentials is found not to provide any simple, reliable correlation with oxygen tolerance. Oxygen tolerance is largely conferred by a single cysteine (C19), replacement of which by glycine removes the ability to function even in 1% O(2).

Item Type: Paper
Subjects: bioinformatics > genomics and proteomics > design > amino acid design
bioinformatics > genomics and proteomics > alignment > sequence alignment
organism description > bacteria > escherichia coli
CSHL Authors:
Communities: CSHL labs > Lukey lab
Depositing User: Adrian Gomez
Date: 26 October 2011
Date Deposited: 28 Jan 2020 16:17
Last Modified: 28 Jan 2020 16:17
Related URLs:
URI: https://repository.cshl.edu/id/eprint/38940

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