Linked Life Data

10600375

Source:http://linkedlifedata.com/resource/pubmed/id/10600375

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2000-1-11
pubmed:abstractText
The Pseudomonas secretin XcpQ forms an oligomeric complex, which is involved in the translocation of proteins across the outer membrane via the type II secretion pathway. Pseudomonas aeruginosa produces only small amounts of this complex, 50 to 100 copies per bacterium, and overexpression is lethal to these cells. However, overexpression of Pseudomonas alcaligenes XcpQ could be achieved in the P. alcaligenes mutant strain 537. Protease protection experiments with P. alcaligenes XcpQ showed that the C-terminal domain of XcpQ, which is conserved in all the different members of the secretin family, is largely resistant to proteinase K. This protease-resistant fragment is embedded in the membrane and remains a stable complex, indicating that this domain is involved in complex formation. Both the intact and the protease-protected XcpQ complex showed a tendency to form two-dimensional crystal-like structures. Electron microscopic analysis of these structures showed that the overall oligomeric rings of the intact and of the protease-resistant complex are highly similar. The central cavity of the intact XcpQ complex contains structured mass. Both the intact and the protease-protected XcpQ complex showed pore-forming activity in planar lipid bilayers, consistent with their role as a translocation channel. However, the single-channel conductances observed were not uniform. Together, these results demonstrate that the C-terminal secretin homology domain of XcpQ is the structural domain that forms the channel through which macromolecules are being transported.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
294
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1169-79
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10600375-Bacterial Proteins, pubmed-meshheading:10600375-Circular Dichroism, pubmed-meshheading:10600375-Conserved Sequence, pubmed-meshheading:10600375-Crystallization, pubmed-meshheading:10600375-Electric Conductivity, pubmed-meshheading:10600375-Endopeptidase K, pubmed-meshheading:10600375-Genes, Bacterial, pubmed-meshheading:10600375-Lipid Bilayers, pubmed-meshheading:10600375-Membrane Proteins, pubmed-meshheading:10600375-Microscopy, Electron, pubmed-meshheading:10600375-Molecular Weight, pubmed-meshheading:10600375-Mutation, pubmed-meshheading:10600375-Porins, pubmed-meshheading:10600375-Protein Structure, Quaternary, pubmed-meshheading:10600375-Protein Structure, Secondary, pubmed-meshheading:10600375-Protein Structure, Tertiary, pubmed-meshheading:10600375-Pseudomonas, pubmed-meshheading:10600375-Pseudomonas aeruginosa, pubmed-meshheading:10600375-Recombinant Proteins, pubmed-meshheading:10600375-Sequence Homology, Amino Acid, pubmed-meshheading:10600375-Structure-Activity Relationship, pubmed-meshheading:10600375-Trypsin
pubmed:year
1999
pubmed:articleTitle
The C-terminal domain of the Pseudomonas secretin XcpQ forms oligomeric rings with pore activity.
pubmed:affiliation
Department of Molecular Microbiology, Utrecht University, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't