Crystal Structure Analysis of the Repair of Iron Centers Protein YtfE and Its Interaction with NO
Journal
Chemistry - A European Journal
Journal Volume
22
Journal Issue
28
Pages
9768-9776
Date Issued
2016
Author(s)
Lo F
Hsieh C
Chen C
Ko T
Horng Y
Lai Y
Chiang Y
Chou C
Chiang C
Huang W
Lin Y
Bohle D.S
Liaw W.
Abstract
Molecular mechanisms underlying the repair of nitrosylated [Fe–S] clusters by the microbial protein YtfE remain poorly understood. The X-ray crystal structure of YtfE, in combination with EPR, magnetic circular dichroism (MCD), UV, and17O-labeling electron spin echo envelope modulation measurements, show that each iron of the oxo-bridged FeII–FeIIIdiiron core is coordinatively unsaturated with each iron bound to two bridging carboxylates and two terminal histidines in addition to an oxo-bridge. Structural analysis reveals that there are two solvent-accessible tunnels, both of which converge to the diiron center and are critical for capturing substrates. The reactivity of the reduced-form FeII–FeIIYtfE toward nitric oxide demonstrates that the prerequisite for N2O production requires the two iron sites to be nitrosylated simultaneously. Specifically, the nitrosylation of the two iron sites prior to their reductive coupling to produce N2O is cooperative. This result suggests that, in addition to any repair of iron centers (RIC) activity, YtfE acts as an NO-trapping scavenger to promote the NO to N2O transformation under low NO flux, which precedes nitrosative stress. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Subjects
nitric oxide; non-heme diiron; protein structures; proteins
Other Subjects
Amino acids; Carboxylation; Dichroism; Electron spin resonance spectroscopy; Magnetic moments; Nitric oxide; Proteins; Repair; Bridging carboxylates; Co-ordinatively unsaturated; Crystal structure analysis; Electron spin-echo envelope modulations; Magnetic circular dichroisms; non-heme diiron; Protein structures; X ray crystal structures; Crystal structure; iron; metalloprotein; nitric oxide; chemistry; circular dichroism; metabolism; molecular model; X ray crystallography; Circular Dichroism; Crystallography, X-Ray; Iron; Metalloproteins; Models, Molecular; Nitric Oxide
Type
journal article