Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
2000-10-23
pubmed:abstractText
MscL, a mechanosensitive channel found in many bacteria, protects cells from hypotonic shock by reducing intracellular pressure through release of cytoplasmic osmolytes. First isolated from Escherichia coli, this protein has served as a model for how a protein senses and responds to membrane tension. Recently the structure of a functionally uncharacterized MscL homologue from Mycobacterium tuberculosis was solved by x-ray diffraction to a resolution of 3.5 A. Here we demonstrate that the protein forms a functional MscL-like mechanosensitive channel in E. coli membranes and azolectin proteoliposomes. Furthermore, we show that M. tuberculosis MscL crystals, when re-solubilized and reconstituted, yield wild-type channel currents in patch clamp, demonstrating that the protein does not irreversibly change conformation upon crystallization. Finally, we apply functional clues acquired from the E. coli MscL to the M. tuberculosis channel and show a mechanistic correlation between these channels. However, the inability of the M. tuberculosis channel to gate at physiological membrane tensions, demonstrated by in vivo E. coli expression and in vitro reconstitution, suggests that the membrane environment or other additional factors influence the gating of this channel.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
31121-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10846181-Bacterial Proteins, pubmed-meshheading:10846181-Cell Membrane, pubmed-meshheading:10846181-Cloning, Molecular, pubmed-meshheading:10846181-Crystallography, pubmed-meshheading:10846181-DNA Mutational Analysis, pubmed-meshheading:10846181-Escherichia coli, pubmed-meshheading:10846181-Escherichia coli Proteins, pubmed-meshheading:10846181-Ion Channels, pubmed-meshheading:10846181-Kinetics, pubmed-meshheading:10846181-Models, Molecular, pubmed-meshheading:10846181-Mutagenesis, Site-Directed, pubmed-meshheading:10846181-Mutation, pubmed-meshheading:10846181-Mycobacterium tuberculosis, pubmed-meshheading:10846181-Patch-Clamp Techniques, pubmed-meshheading:10846181-Phenotype, pubmed-meshheading:10846181-Phosphatidylcholines, pubmed-meshheading:10846181-Phospholipids, pubmed-meshheading:10846181-Protein Conformation, pubmed-meshheading:10846181-Proteolipids, pubmed-meshheading:10846181-Structure-Activity Relationship, pubmed-meshheading:10846181-Time Factors, pubmed-meshheading:10846181-X-Ray Diffraction
pubmed:year
2000
pubmed:articleTitle
Correlating a protein structure with function of a bacterial mechanosensitive channel.
pubmed:affiliation
Department of Physiology, University of Texas-Southwestern Medical Center, Dallas, Texas 75390-9040, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't