Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-3-12
pubmed:abstractText
TolAI--II--beta-lactamase, a fusion protein consisting of the inner membrane and transperiplasmic domains of TolA followed by TEM--beta-lactamase associated with the inner membrane but remained confined to the cytoplasm when expressed at high level in Escherichia coli. Although the fusion protein was resistant to proteolysis in vivo, it was hydrolyzed during preparative SDS-polyacrylamide electrophoresis and when insoluble cellular fractions unfolded with 5 M urea were subjected to microdialysis. Inhibitor profiling studies revealed that both a metallo- and serine protease were involved in TolAI--II--beta-lactamase degradation under denaturing conditions. The in vitro degradation rates of the fusion protein were not affected when insoluble fractions were harvested from a strain lacking protease IV, but were significantly reduced when microdialysis experiments were conducted with material isolated from an isogenic ftsH1 mutant. Adenine nucleotides were not required for degradation, and ATP supplementation did not accelerate the apparent rate of TolAI--II--beta-lactamase hydrolysis under denaturing conditions. Our results indicate that the metalloprotease active site of FtsH remains functional in the presence of 3--5 M urea and suggest that the ATPase and proteolytic activities of FtsH can be uncoupled if the substrate is sufficiently unstructured. Thus, a key role of the FtsH AAA module appears to be the net unfolding of bound substrates so that they can be efficiently engaged by the protease active site.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/ATP-Dependent Proteases, http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate, http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins, http://linkedlifedata.com/resource/pubmed/chemical/FtsH protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Metalloendopeptidases, http://linkedlifedata.com/resource/pubmed/chemical/Protease Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Urea, http://linkedlifedata.com/resource/pubmed/chemical/beta-Lactamases, http://linkedlifedata.com/resource/pubmed/chemical/beta-lactamase TEM-1, http://linkedlifedata.com/resource/pubmed/chemical/tolA protein, E coli
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1046-5928
pubmed:author
pubmed:copyrightInfo
Copyright 2001 Academic Press.
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
323-32
pubmed:dateRevised
2010-10-8
pubmed:meshHeading
pubmed-meshheading:11237695-ATP-Dependent Proteases, pubmed-meshheading:11237695-Adenosine Triphosphate, pubmed-meshheading:11237695-Bacterial Proteins, pubmed-meshheading:11237695-Cell Membrane, pubmed-meshheading:11237695-Escherichia coli, pubmed-meshheading:11237695-Escherichia coli Proteins, pubmed-meshheading:11237695-Membrane Proteins, pubmed-meshheading:11237695-Metalloendopeptidases, pubmed-meshheading:11237695-Protease Inhibitors, pubmed-meshheading:11237695-Protein Binding, pubmed-meshheading:11237695-Protein Denaturation, pubmed-meshheading:11237695-Protein Structure, Tertiary, pubmed-meshheading:11237695-Protein Transport, pubmed-meshheading:11237695-Recombinant Fusion Proteins, pubmed-meshheading:11237695-Solubility, pubmed-meshheading:11237695-Urea, pubmed-meshheading:11237695-beta-Lactamases
pubmed:year
2001
pubmed:articleTitle
Escherichia coli FtsH (HflB) degrades a membrane-associated TolAI-II-beta-lactamase fusion protein under highly denaturing conditions.
pubmed:affiliation
Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't