Premium
Effects of the loss of the axial tyrosine ligand of the low‐spin heme of MauG on its physical properties and reactivity
Author(s) -
Abu Tarboush Nafez,
Shin Sooim,
Geng Jiafeng,
Liu Aimin,
Davidson Victor L.
Publication year - 2012
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2012.10.044
Subject(s) - chemistry , heme , redox , reactivity (psychology) , cofactor , tyrosine , ligand (biochemistry) , hemeprotein , biochemistry , enzyme , inorganic chemistry , receptor , pathology , medicine , alternative medicine
MauG catalyzes posttranslational modifications of methylamine dehydrogenase to complete the biosynthesis of its protein‐derived tryptophan tryptophylquinone (TTQ) cofactor. MauG possesses a five‐coordinate high‐spin and a six‐coordinate low‐spin ferric heme, the latter with His‐Tyr ligation. Replacement of this tyrosine with lysine generates a MauG variant with only high‐spin ferric heme and altered spectroscopic and redox properties. Y294K MauG cannot stabilize the bis ‐Fe(IV) redox state required for TTQ biosynthesis but instead forms a compound I‐like species on reaction with peroxide. The results clarify the role of Tyr ligation of the five‐coordinate heme in determining the physical and redox properties and reactivity of MauG.