Amino acids side-chain ligand switch

Such an involvement of an amino acid side-chain ligand switch within each catalytic cycle was a novel proposal and as such needs to be scrutinized by a variety of experimental procedures as well as analysis in the context of information known for cytochrome cd nitrite reductase from another source (see later discussion). However, it is interesting to note that something similar has been proposed for the protocate-chuate 3,4-dioxygenase enzyme from Pseudomonas putida (15). On the other hand, bacterial cytochrome c peroxidase offers an example where ligand switching seemingly relates only to an activation phenomenon. 

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