Linked Life Data

17925395

Source:http://linkedlifedata.com/resource/pubmed/id/17925395

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
52
pubmed:dateCreated
2007-12-24
pubmed:abstractText
Globin-coupled sensors (GCSs) are multiple-domain transducers, consisting of a regulatory globin-like heme-binding domain and a linked transducer domain(s). GCSs have been described in both Archaea and bacteria. They are generally assumed to bind O(2) (and perhaps other gaseous ligands) and to transmit a conformational change signal through the transducer domain in response to fluctuating O(2) levels. In this study, the heme-binding domain, AvGReg178, and the full protein, AvGReg of the Azotobacter vinelandii GCS, were cloned, expressed, and purified. After purification, the heme iron of AvGReg178 was found to bind O(2). This form was stable over many hours. In contrast, the predominant presence of a bis-histidine coordinate heme in ferric AvGReg was revealed. Differences in the heme pocket structure were also observed for the deoxygenated ferrous state of these proteins. The spectra showed that the deoxygenated ferrous derivatives of AvGReg178 and AvGReg are characterized by a penta-coordinate and hexa-coordinate heme iron, respectively. O(2) binding isotherms indicate that AvGReg178 and AvGReg show a high affinity for O(2) with P(50) values at 20 degrees C of 0.04 and 0.15 torr, respectively. Kinetics of CO binding indicate that AvGReg178 carbonylation conforms to a monophasic process, comparable with that of myoglobin, whereas AvGReg carbonylation conforms to a three-phasic reaction, as observed for several proteins with bis-histidine heme iron coordination. Besides sensing ligands, in vitro data suggest that AvGReg(178) may have a role in O(2)-mediated NO-detoxification, yielding metAvGReg(178) and nitrate.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
37325-40
pubmed:meshHeading
pubmed-meshheading:17925395-Amino Acid Sequence, pubmed-meshheading:17925395-Azotobacter vinelandii, pubmed-meshheading:17925395-Bacterial Proteins, pubmed-meshheading:17925395-Escherichia coli, pubmed-meshheading:17925395-Gene Expression Regulation, Bacterial, pubmed-meshheading:17925395-Heme, pubmed-meshheading:17925395-Hemeproteins, pubmed-meshheading:17925395-Histidine, pubmed-meshheading:17925395-Iron, pubmed-meshheading:17925395-Kinetics, pubmed-meshheading:17925395-Ligands, pubmed-meshheading:17925395-Models, Biological, pubmed-meshheading:17925395-Molecular Sequence Data, pubmed-meshheading:17925395-Nitric Oxide, pubmed-meshheading:17925395-Oxygen, pubmed-meshheading:17925395-Protein Structure, Tertiary, pubmed-meshheading:17925395-Sequence Homology, Amino Acid, pubmed-meshheading:17925395-Spectrum Analysis, Raman, pubmed-meshheading:17925395-Time Factors
pubmed:year
2007
pubmed:articleTitle
Characterization of a globin-coupled oxygen sensor with a gene-regulating function.
pubmed:affiliation
Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't