Linked Life Data

15046586

Source:http://linkedlifedata.com/resource/pubmed/id/15046586

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 2
pubmed:dateCreated
2004-3-29
pubmed:abstractText
Methanopyrus kandleri is a hyperthermophilic methanogenic archaeon, which grows on H(2) and CO(2) as its sole energy source. Its growth temperature optimum is 98 degrees C. One of the interesting characteristics of this archaeon is its high intracellular salt content. The organism has been reported to contain the trianionic cDPG (cyclic 2,3-diphosphoglycerate) and K+ at concentrations of 1.1 and 3 M, respectively. Reflecting the high cellular salt concentration, the enzymes in this organism are adapted not only to high temperature but also to high salt concentrations. The formyltransferase from M. kandleri was characterized extensively with respect to thermo- and halophilicity. The crystal structure of the formyltransferase at 1.73 A shows the enzyme to be composed of four identical subunits of molecular mass 32 kDa. The formyltransferase is thermostable and active only at relatively high concentrations of potassium phosphate (1 M) or other salts with strongly hydrated anions (strong salting-out salts). Potassium phosphate and potassium cDPG were found to be equivalent in activating and stabilizing the enzyme. At low concentrations of these salts, the enzyme is inactive and thermolabile. It was shown by equilibrium sedimentation analysis that the enzyme is in a monomer/dimer/tetramer equilibrium, the equilibrium constant being dependent on the concentration of salts: the higher oligomeric species increase with increasing salt concentrations. Evidence was provided that the monomer is both inactive and thermolabile. Experiments using a mutation which is directed to break surface ion pairs between two dimers indicated that dimerization is required for activity and tetramerization leads to thermostability.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0300-5127
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
269-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Hyperthermophilic and salt-dependent formyltransferase from Methanopyrus kandleri.
pubmed:affiliation
Max-Planck-Institut für terrestrische Mikrobiologie and Fachbereich Biologie, Philipps-Universität, Karl-von-Frisch Strasse, 35043 Marburg, Germany. shima@staff.uni-marburg.de
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't