Ring-like pore structures of SecA: Implication for bacterial protein-conducting channels
AUTOR(ES)
Wang, Hong-Wei
FONTE
The National Academy of Sciences
RESUMO
SecA, an essential component of the general protein secretion pathway of bacteria, is present in Escherichia coli as soluble and membrane-integral forms. Here we show by electron microscopy that SecA assumes two characteristic forms in the presence of phospholipid monolayers: dumbbell-shaped elongated structures and ring-like pore structures. The ring-like pore structures with diameters of 8 nm and holes of 2 nm are found only in the presence of anionic phospholipids. These ring-like pore structures with larger 3- to 6-nm holes (without staining) were also observed by atomic force microscopic examination. They do not form in solution or in the presence of uncharged phosphatidylcholine. These ring-like phospholipid-induced pore-structures may form the core of bacterial protein-conducting channels through bacterial membranes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=153074Documentos Relacionados
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