Ligninolytic peroxidases

As in the other members of the superfamily, the heme pocket of ligninolytic peroxidases includes two conserved histidine residues disposed above and below the heme plane (Fig. 3.4a). The second histidine acts as the fifth ligand of the heme iron, occupying a proximal position, while the first one is at a higher distance being, therefore, called distal histidine (by extension, the regions located below and above the heme plane are also called proximal and distal regions). 

Four more amino acid residues are conserved at the distal (arginine and phenylalanine) and proximal (aspartate and phenylalanine) sides of the heme pocket in all structurally characterized ligninolytic peroxidases [33], two of them (distal arginine and proximal aspartate) also being conserved in the other members of the superfamily. 

Miki Y, Morales M, Ruiz-Duenas FJ et al (2009) Escherichia coli expression and in vitro activation of a unique ligninolytic peroxidase that has a catalytic tyrosine residue. Protein Express Purif 68 208-214... 

Our laboratory is also studying the directed evolution of a new type of potentially ligninolytic peroxidase classified as unspecific peroxygenase, UPO (EG 1.11.2.1). UPO was initially defined as a heme-thiolate peroxidase, exhibiting both per-oxidative and peroxygenative activities toward aromatic compounds (aromatic peroxygenase, also referred to as APO [26, 75]). However, more recent studies have described the monooxygenase activity of UPO toward ahphatic compounds (UPO,... 

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