Linked Life Data

19132843

Source:http://linkedlifedata.com/resource/pubmed/id/19132843

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2009-2-5
pubmed:abstractText
Ferredoxin:thioredoxin reductase catalyzes the reduction of thioredoxins in plant chloroplasts using the [Fe2S2] ferredoxin as a one-electron donor and as such plays a central role in light regulation of oxygenic photosynthesis. The active-site comprises a [Fe4S4] cluster next to a redox-active disulfide that is cleaved in sequential one-electron steps and the combination of spectroscopic and crystallographic studies have revealed a catalytic mechanism involving novel site specific cluster chemistry in the oxidized, one-electron- and two-electron-reduced redox states. Histidine-86 has emerged as a potential proton donor/acceptor in the catalytic mechanism based on redox-related changes in the positioning of the imidazole ring during redox cycling and greatly decreased activity for the H86Y variant. Here we report on spectroscopic and redox characterization of the [Fe4S4] center in Synechocystis sp. PCC 6803 H86Y ferredoxin:thoredoxin reductase in the accessible redox states of both the as purified and N-ethylmaleimide-modified forms, using the combination of UV-visible absorption and variable-temperature magnetic circular dichroism, EPR, resonance Raman and Mössbauer spectroscopies. The results demonstrate that His86 is required for formation of the partially valence-localized [Fe4S4]2+ cluster that is the hallmark of two-electron-reduced intermediate. Taken together with the available structural data, the spectroscopic results indicate a functional role for His86 in protonation/deprotonation of the cluster-interacting thiol and anchoring the cluster interacting thiol in close proximity to the cluster in the two-electron-reduced intermediate.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-10649999, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-11852093, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-11898432, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-12553798, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-12626118, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-14769790, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-15984889, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-16218868, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-17611542, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-17612488, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-18377232, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-3028266, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-8277866, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-8784198, http://linkedlifedata.com/resource/pubmed/commentcorrection/19132843-9521781
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1520-4995
pubmed:author
pubmed:issnType
Electronic
pubmed:day
10
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1016-24
pubmed:dateRevised
2011-1-7
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Role of histidine-86 in the catalytic mechanism of ferredoxin:thioredoxin reductase.
pubmed:affiliation
Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, N.I.H., Extramural