Purification, reconstitution, and characterization of the CpxRAP envelope stress system of Escherichia coli.

In Escherichia coli the Cpx sensor regulator system senses different kinds of envelope stress and responds by triggering the expression of periplasmic folding factors and proteases. It consists of the membrane-anchored sensor kinase CpxA, the response regulator CpxR, and the periplasmic protein CpxP. The Cpx pathway is induced in vivo by a variety of signals including pH variation, osmotic stress, and misfolded envelope proteins and is inhibited by overproduced CpxP.

Identification of a gene cluster encoding an arginine ATP-binding-cassette transporter in the genome of the thermophilic Gram-positive bacterium Geobacillus stearothermophilus strain DSMZ 13240.

A single gene cluster encoding components of a putative ATP-binding cassette (ABC) transporter for basic amino acids was identified in the incomplete genome sequence of the thermophilic Gram-positive bacterium Geobacillus stearothermophilus by blast searches. The cluster comprises three genes, and these were amplified from chromosomal DNA of G. stearothermophilus, ligated into plasmid vectors and expressed in Escherichia coli.

Functional reconstitution of a maltose ATP-binding cassette transporter from the thermoacidophilic gram-positive bacterium Alicyclobacillus acidocaldarius.

The thermoacidophilic gram-positive bacterium Alicyclobacillus acidocaldarius grows at 60 degrees C and pH 2-3. The organism can utilize maltose and maltodextrins as energy source that are taken up by an ATP-binding cassette (ABC) import system. Genes encoding a maltose binding protein, MalE, and two membrane-integral subunits, MalF and MalG, are clustered on the chromosome but a malK gene translating into a cognate ATPase subunit is lacking.