Precursor protein translocation across the Escherichia coli inner membrane is mediated by the translocase, which is composed of a heterotrimeric integral membrane protein complex with SecY, SecE, and SecG as subunits and peripherally bound SecA. Cross-linking experiments were conducted to study which proteins are associated with SecA in vivo. Formaldehyde treatment of intact cells results in th...

Bacterial cell surface display is a widely used technology for bioadsorption and for the development of a variety of screening systems. Magnetotactic bacteria are unique species of bacteria due to the presence of magnetic nanoparticles within them. These intracellular, nanosized (50 to 100 nm) magnetic nanoparticles enable the cells to migrate and be manipulated by magnetic force. In this work,...

Escherichia coli K1 is a leading pathogen in neonatal sepsis and meningitis. The K1 capsule, composed of alpha2,8-linked polysialic acid, represents the major virulence factor. In some K1 strains, phase-variable O-acetylation of the capsular polysaccharide is observed, a modification that is catalyzed by the prophage-encoded O-acetyltransferase NeuO. Phase variation is mediated by changes in th...

This work describes the synthesis and use of the chelator lipid, nitrilotriacetic acid ditetradecylamine (NTA-DTDA). This lipid is readily dispersed in aqueous media, both alone and when mixed with carrier lipids like dimyristoylphosphatidylcholine (DMPC). Fluorescence microscopic examination of membranes deposited from NTA-DTDA-containing liposomes shows that NTA-DTDA mixes uniformly with the ...

Protein-protein interactions play key roles in protein function and the structural organization of a cell. A thorough description of these interactions should facilitate elucidation of cellular activities, targeted-drug design, and whole cell engineering. A large-scale comprehensive pull-down assay was performed using a His-tagged Escherichia coli ORF clone library. Of 4339 bait proteins tested...

FhuA (Mr 78,992, 714 amino acids), siderophore receptor for ferrichrome-iron in the outer membrane of Escherichia coli, was affinity tagged, rapidly purified, and crystallized. To obtain FhuA in quantities sufficient for crystallization, a hexahistidine tag was genetically inserted into the fhuA gene after amino acid 405, which resides in a known surface-exposed loop. Recombinant FhuA405.H6 was...

Ku is an ubiquitous nuclear heterodimeric protein consisting of p70 and p86 subunits that binds double-stranded DNA termini and associates with chromosomes in vivo. It was originally described as an autoantigen in patients with certain autoimmune diseases. The individual subunits of Ku have been difficult to isolate from human cells without denaturation and attempts to produce functional recomb...

The alpha1- and beta1-subunits of human soluble guanylate cyclase (sGC) were coexpressed in the Sf9 cells/baculovirus system. In addition to the native enzyme, constructs with hexahistidine tag at the amino and carboxyl termini of each subunit were coexpressed. This permitted the rapid and efficient purification of active recombinant enzyme on a nickel-affinity column. The enzyme has one heme p...

Karim Saei was born in 1910, in Mashhad, north eastern Iran, where he got his diploma. He left behind his homeland for Karaj city to study at the Faculty of Agriculture of Tehran University. He passed his course very successfully and received his B.Sc. degree in 1931 followed by a scholarship to study for 2 years at Agronomic Institute in Montpellier, France. He graduated M.Sc. with excellent g...

Bahaodoleh Razi Tarashti was born in taTarasht village of Rey (in northwest of present Tehran). He ended up the medical education in Rey and trend to practicing and learning medicine contemporary as spiritual guide of Noorbakhshi group. Although the birthday of Bahaodoleh is not clear exactly, bases on evidences, he probably has been killed in fractional struggle by agents of king Esmaeel Safav...