5 research outputs found
Rediscovery of the Endangered Carchi Andean Toad, Rhaebo colomai (Hoogmoed, 1985), in Ecuador, with comments on its conservation status and extinction risk
Since 1984 there have been no records of Rhaebo colomai (Hoogmoed, 1985) within the territory of Ecuador. This species was known from 2 localities in the province of Carchi, northwestern Ecuador, and the department of Nari��o, southwestern Colombia, which were reported in 1979 and 2015, respectively. We report the recent sightings of R. colomai at 3 new localities in Ecuador and discuss and evaluate this species��� extinction risk and conservation status
Ring-like pore structures of SecA: Implication for bacterial protein-conducting channels
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