In:
Chemistry – A European Journal, Wiley, Vol. 22, No. 28 ( 2016-07-04), p. 9768-9776
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, and 17 O‐labeling electron spin echo envelope modulation measurements, show that each iron of the oxo‐bridged Fe II –Fe III diiron 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 Fe II –Fe II YtfE toward nitric oxide demonstrates that the prerequisite for N 2 O 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 N 2 O 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 N 2 O transformation under low NO flux, which precedes nitrosative stress.
Type of Medium:
Online Resource
ISSN:
0947-6539
,
1521-3765
DOI:
10.1002/chem.201600990
Language:
English
Publisher:
Wiley
Publication Date:
2016
detail.hit.zdb_id:
1478547-X
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