Diversity Of Structures, Catalytic Mechanisms And Processes Of Cofactor Biosynthesis Of Tryptophylquinone-Bearing Enzymes

Keywords

Amine dehydrogenase; Amine oxidase; Posttranslational modification; Quinoprotein; Redox cofactor; Tryptophan

Abstract

Tryptophyquinone-bearing enzymes contain protein-derived cofactors formed by posttranslational modifications of Trp residues. Tryptophan tryptophylquinone (TTQ) is comprised of a di-oxygenated Trp residue, which is cross-linked to another Trp residue. Cysteine tryptophylquinone (CTQ) is comprised of a di-oxygenated Trp residue, which is cross-linked to a Cys residue. Despite the similarity of these cofactors, it has become evident in recent years that the overall structures of the enzymes that possess these cofactors vary, and that the gene clusters that encode the enzymes are quite diverse. While it had been long assumed that all tryptophylquinone enzymes were dehydrogenases, recently discovered classes of these enzymes are oxidases. A common feature of enzymes that have these cofactors is that the posttranslational modifications that form the mature cofactors are catalyzed by a modifying enzyme. However, it is now clear that modifying enzymes are different for different tryptophylquinone enzymes. For methylamine dehydrogenase a di-heme enzyme, MauG, is needed to catalyze TTQ biosynthesis. However, no gene similar to mauG is present in the gene clusters that encode the other enzymes, and the recently characterized family of CTQ-dependent oxidases, termed LodA-like proteins, require a flavoenzyme for cofactor biosynthesis.

Publication Date

9-15-2018

Publication Title

Archives of Biochemistry and Biophysics

Volume

654

Number of Pages

40-46

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/j.abb.2018.07.012

Socpus ID

85049982679 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85049982679

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