Linked Life Data

9141355

Source:http://linkedlifedata.com/resource/pubmed/id/9141355

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-6-10
pubmed:abstractText
In the search for the essential functional domains of the large mechanosensitive ion channel (MscL) of E. coli, we have cloned several mutants of the mscL gene into a glutathione S-transferase fusion protein expression system. The resulting mutated MscL proteins had either amino acid additions, substitutions or deletions in the amphipathic N-terminal region, and/or deletions in the amphipathic central or hydrophilic C-terminal regions. Proteolytic digestion of the isolated fusion proteins by thrombin yielded virtually pure recombinant MscL proteins that were reconstituted into artificial liposomes and examined for function by the patch-clamp technique. The addition of amino acid residues to the N-terminus of the MscL did not affect channel activity, whereas N-terminal deletions or changes to the N-terminal amino acid sequence were poorly tolerated and resulted in channels exhibiting altered pressure sensitivity and gating. Deletion of 27 amino acids from the C-terminus resulted in MscL protein that formed channels similar to the wild-type, while deletion of 33 C-terminal amino acids extinguished channel activity. Similarly, deletion of the internal amphipathic region of the MscL abolished activity. In accordance with a recently proposed spatial model of the MscL, our results suggest that (i) the N-terminal portion participates in the channel activation by pressure, and (ii) the essential channel functions are associated with both, the putative central amphipathic alpha-helical portion of the protein and the six C-terminal residues RKKEEP forming a charge cluster following the putative M2 membrane spanning alpha-helix.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-2631
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
157
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17-25
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Molecular dissection of the large mechanosensitive ion channel (MscL) of E. coli: mutants with altered channel gating and pressure sensitivity.
pubmed:affiliation
Department of Pharmacology, University of Western Australia, Nedlands WA 6907, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't