The LptA protein of Escherichia coli has been implicated in the transport of lipopolysaccharide (LPS) from the inner membrane to the outer membrane. Here we provide evidence that LptA binds structurally diverse LPS substrates in vitro and demonstrate that it interacts specifically with the lipid A domain of LPS. These results are consistent with LptA playing a chaperone role in the transport of...

The putative multi-copper oxidase CueO had previously been implicated in intrinsic copper resistance in Escherichia coli. In this report we showed that the presence of CueO in the periplasm protected alkaline phosphatase from copper-induced damage. CueO contained four copper atoms per molecule and displayed spectroscopic properties typical of blue copper oxidases. CueO catalyzed the oxidation o...

Variants of lambda repressor and cytochrome b562 translated from messenger RNAs without stop codons were modified by carboxyl terminal addition of an ssrA-encoded peptide tag and subsequently degraded by carboxyl terminal-specific proteases present in both the cytoplasm and periplasm of Escherichia coli. The tag appears to be added to the carboxyl terminus of the nascent polypeptide chain by co...

Gamma-ray-irradiated Escherichia coli CR thy(-) cells and spheroplasts, prelabeled with (14)C-thymine, were assayed for acid-insoluble activity as a function of incubation time after irradiation. Under similar irradiation and incubation conditions, degradation profiles of cells and spheroplasts were virtually identical. Similar results were found for cells and protoplasts irradiated in the pres...

Protein disulfide bond formation is catalyzed by a series of Dsb enzymes present in the periplasm of Escherichia coli. The crystal structure of the DsbB-DsbA-ubiquinone ternary complex provided important insights into mechanisms of the de novo disulfide bond generation cooperated by DsbB and ubiquinone and of the disulfide bond shuttle from DsbB to DsbA. The structural basis for prevention of t...

The structure of the membrane protein MntB, a component of a manganese transporter system in Synechocystis sp. strain PCC 6803, was examined with a series of fusions to the reporter proteins alkaline phosphatase and beta-galactosidase. The results support a topological model for MntB consisting of nine transmembrane segments, with the amino terminus of the protein being in the periplasm and the...

Shewanella sp. strain F1, isolated from a lab-scale Fe(II)−dependent anaerobic denitrifying reactor, could reduce nitrate by oxidizing Fe(II). Its reduction rate and Fe(II) oxidation were 0.48 mg/(L·h) 5.05 at OD600 of 0.4786 with five-fold diluent. was popular in Fe(III) reduction. Fewer studies about its ability for are available. The low pH determined to be the switch F1 perform or oxidation...

Abstract In Pseudomonas aeruginosa , Ttg2D is the soluble periplasmic phospholipid-binding component of an ABC transport system thought to be involved in maintaining asymmetry outer membrane. Here we use crystallographic structure at 2.5 Å resolution reveal that this protein can accommodate four acyl chains. Analysis available structures orthologs shows they conform a new substrate-binding-prot...