Linked Life Data

10231537

Source:http://linkedlifedata.com/resource/pubmed/id/10231537

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1999-6-1
pubmed:abstractText
Earlier studies reported that Pseudomonas aeruginosa exoenzyme S (ExoS) possessed an absolute requirement for the eukaryotic protein factor activating exoenzyme S (FAS) for expressing ADP-ribosyltransferase activity. During the characterization of a serum-derived FAS-like activity, we observed the ability of a catalytic deletion peptide of ExoS (DeltaN222) to ADP-ribosylate target proteins in the absence of FAS. Characterization of the activation of DeltaN222 by FAS provided an opportunity to gain insight into the mechanism of ExoS activation by FAS. Under standard enzyme assay conditions, the initial rate of FAS-independent ADP-ribosyltransferase activity of DeltaN222 was not linear with time and rapidly approached zero. Dilution into high-ionic strength buffers stabilized DeltaN222 so it could express FAS-independent ADP-ribosyltransferase activity at a linear rate. This stabilization was a general salt effect, since dilution into a 1.0 M solution of either NaCH3COOH, NaCl, or KCl stabilized the ADP-ribosyltransferase activity of DeltaN222. Kinetic analysis in a high-ionic strength buffer showed that FAS enhanced the catalytic activity of DeltaN222 by increasing the affinity for NAD and stimulating the turnover rate. Velocity experiments indicated that the stabilization of DeltaN222 by high salt was not functionally identical to stabilization by FAS. Together, these data implicate a dual role for FAS in the allosteric activation of ExoS, involving both substrate binding and catalysis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5858-63
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Expression of FAS-independent ADP-ribosyltransferase activity by a catalytic deletion peptide of Pseudomonas aeruginosa exoenzyme S.
pubmed:affiliation
Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee 53226, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.