A method for separating the outer and inner membranes of Pseudomonas aeruginosa PAO1 in the absence of added ethylenediaminetetraacetic acid was devised. The method yields two outer membrane fractions which show the same protein pattern on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but differ substantially in their relative contents of phospholipids. One of these outer membrane ...

During evolution, chloroplasts have relinquished the majority of their genes to the nucleus. The products of transferred genes are imported into the organelle with the help of an import machinery that is distributed across the inner and outer plastid membranes. The evolutionary origin of this machinery is puzzling because, in the putative predecessors, the cyanobacteria, the outer two membranes...

The hemolytic phenotype in Escherichia coli is determined by four genes. Two (hlyC and hlyA) determine the synthesis of a hemolytically active protein which is transported across the cytoplasmic membrane. The other two genes (hlyBa and hlyBb) encode two proteins which are located in the outer membrane and seem to form a specific transport system for hemolysin across the outer membrane. The prim...

The Pseudomonas aeruginosa mutant Z61 has been shown to be highly supersusceptible to a wide range of antibiotics, including beta-lactams, aminoglycosides, rifampin, tetracycline, and chloramphenicol (W. Zimmerman, Int. J. Clin. Pharmacol. Biopharm. 17:131-134, 1979). Spontaneous revertants were isolated, using gentamicin or carbenicillin as selective agents, and shown to have two patterns of s...

Specific labeling of a single row of cellulose-synthesizing complexes (terminal complexes, TC subunits, TCs, or TC arrays) in Acetobacter xylinum by antibodies raised against a 93-kDa protein (the cyclic dignanylic acid-binding protein) has been demonstrated by using the sodium dodecyl sulfate (SDS)-freeze-fracture labeling (FRL) technique. The antibodies to the 93-kDa protein specifically reco...

A plasmid, pWEH1, was constructed containing a fusion of the DNA encoding the signal sequence of the Escherichia coli outer-membrane protein A to the 5'-end of a glyceraldehyde-3-phosphate dehydrogenase cDNA from Ricinus communis. When expressed in E. coli, the fusion protein was secreted by the normal membrane-potential-dependent pathway. Processing by signal peptidase was inhibited by low con...

One of the main fundamental mechanisms of antibiotic resistance in Gram-negative bacteria comprises an effective change in the membrane permeability to antibiotics. The Gram-negative bacterial complex cell envelope comprises an outer membrane that delimits the periplasm from the exterior environment. The outer membrane contains numerous protein channels, termed as porins or nanopores, which are...

The major protein of the outer mitochondrial membrane of Neurospora was purified. On dodecylsulfate-containing gels it displayed a single band with an apparent molecular weight of 31 000. Reconstitution experiments with artificial lipid bilayers showed that this protein forms pores. Pore conductance was dependent on the voltage across the membrane. The protein inserted into the membrane in an o...