Dataset Information


Regioselectivity of H cluster oxidation.

ABSTRACT: The H(2)-evolving potential of [FeFe] hydrogenases is severely limited by the oxygen sensitivity of this class of enzymes. Recent experimental studies on hydrogenase from C. reinhardtii point to O(2)-induced structural changes in the [Fe(4)S(4)] subsite of the H cluster. Here, we investigate the mechanistic basis of this observation by means of density functional theory. Unexpectedly, we find that the isolated H cluster shows a pathological catalytic activity for the formation of reactive oxygen species such as O(2)(-) and HO(2)(-). After protonation of O(2)(-), an OOH radical may coordinate to the Fe atoms of the cubane, whereas H(2)O(2) specifically reacts with the S atoms of the cubane-coordinating cysteine residues. Both pathways are accompanied by significant structural distortions that compromise cluster integrity and thus catalytic activity. These results explain the experimental observation that O(2)-induced inhibition is accompanied by distortions of the [Fe(4)S(4)] moiety and account for the irreversibility of this process.


PROVIDER: S-EPMC3238416 | BioStudies | 2011-01-01

REPOSITORIES: biostudies

Similar Datasets

2010-01-01 | S-EPMC3057479 | BioStudies
2007-01-01 | S-EPMC1783899 | BioStudies
2008-01-01 | S-EPMC2535771 | BioStudies
2018-01-01 | S-EPMC5866592 | BioStudies
2019-01-01 | S-EPMC6333285 | BioStudies
2001-01-01 | S-EPMC59822 | BioStudies
2019-01-01 | S-EPMC6772009 | BioStudies
2014-01-01 | S-EPMC4210109 | BioStudies
2007-01-01 | S-EPMC2546524 | BioStudies
1000-01-01 | S-EPMC3629468 | BioStudies