Crystal Structure Analysis of the Repair of Iron Centers Protein YtfE and Its Interaction with NO.
Chemistry
; 22(28): 9768-76, 2016 Jul 04.
Article
em En
| MEDLINE
| ID: mdl-27246459
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 N2 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 N2 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 N2 O transformation under low NO flux, which precedes nitrosative stress.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ferro
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Metaloproteínas
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Óxido Nítrico
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article