Publication Date:
2005-07-30
Description:
The protective antigen component of anthrax toxin forms a homoheptameric pore in the endosomal membrane, creating a narrow passageway for the enzymatic components of the toxin to enter the cytosol. We found that, during conversion of the heptameric precursor to the pore, the seven phenylalanine-427 residues converged within the lumen, generating a radially symmetric heptad of solvent-exposed aromatic rings. This "phi-clamp" structure was required for protein translocation and comprised the major conductance-blocking site for hydrophobic drugs and model cations. We conclude that the phi clamp serves a chaperone-like function, interacting with hydrophobic sequences presented by the protein substrate as it unfolds during translocation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1815389/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1815389/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Krantz, Bryan A -- Melnyk, Roman A -- Zhang, Sen -- Juris, Stephen J -- Lacy, D Borden -- Wu, Zhengyan -- Finkelstein, Alan -- Collier, R John -- AI022021/AI/NIAID NIH HHS/ -- AI062204/AI/NIAID NIH HHS/ -- F32 AI062204/AI/NIAID NIH HHS/ -- F32 AI062204-01/AI/NIAID NIH HHS/ -- GM29210/GM/NIGMS NIH HHS/ -- R37 AI022021/AI/NIAID NIH HHS/ -- R37 GM029210/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2005 Jul 29;309(5735):777-81.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16051798" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Amino Acid Substitution
;
Antigens, Bacterial/*chemistry/genetics/*metabolism
;
Bacillus anthracis/*chemistry/metabolism
;
Bacterial Toxins/*chemistry/genetics/*metabolism
;
Binding Sites
;
Cell Membrane/*metabolism
;
Cytosol/metabolism
;
Electron Spin Resonance Spectroscopy
;
Endosomes/metabolism
;
Hydrogen-Ion Concentration
;
Hydrophobic and Hydrophilic Interactions
;
Lipid Bilayers/metabolism
;
Models, Biological
;
Models, Molecular
;
Molecular Sequence Data
;
Mutagenesis
;
Onium Compounds/metabolism
;
Organophosphorus Compounds/metabolism
;
Phenylalanine/*chemistry
;
Protein Conformation
;
Protein Folding
;
Quaternary Ammonium Compounds/metabolism
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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