Recommended Method for Chromosome Exploitation: RMCE-based Cassette-exchange Systems in Animal Cell Biotechnology.

The availability of site-specific recombinases has revolutionized the rational construction of cell lines with predictable properties. Early efforts were directed to providing pre-characterized genomic loci with a single recombinase target site that served as an address for the integration of vectors carrying a compatible tag. Efficient procedures of this type had to await recombinases like PhiC31, which recombine attP and attB target sites in a one-way reaction - at least in the cellular environment of the higher eukaryotic cell.

Enhanceosome formation over the beta interferon promoter underlies a remote-control mechanism mediated by YY1 and YY2.

The expression of beta interferon genes from humans and mice is under the immediate control of a virus-responsive element (VRE) that terminates 110 bp upstream from the transcriptional start site. Whereas a wealth of information is available for the enhanceosome that is formed on the VRE upon the signals generated by viral infection, early observations indicating the existence of other far-upstream control elements have so far remained without a molecular fundament. Guided by a computational analysis of DNA structures, we could locate three as-yet-unknown transcription factor-binding regions at -0.

RAR-beta(1) overexpression in chromophobe renal cell carcinoma: a novel target for therapeutic intervention?

Aim: Retinoic acid (RA) has proven to possess modest but distinct activity in metastatic renal cell carcinoma (RCC), at least in a subgroup of patients. However, the exact molecular mechanisms leading to success or failure of RA application in individual patients are still unknown. As earlier studies have indicated that in RCC the RA receptor (RAR) beta might play a central role in RA signaling, we investigated the expression of the isoforms RAR-beta(1+2) in primary conventional and chromophobe RCC.

Structure and function of radical SAM enzymes.

'Radical SAM' enzymes juxtapose a [4Fe-4S] cluster and S-adenosyl-l-methionine (SAM) to generate catalytic 5'-deoxyadenosyl radicals. The crystal structures of oxygen-independent coproporphyrinogen III oxidase HemN and biotin synthase reveal the positioning of both cofactors with respect to each other and relative to the surrounding protein environment. Each is found in an unprecedented coordination environment including the direct ligation of the [4Fe-4S] cluster by the amino nitrogen and one carboxylate oxygen of the methionine moiety of SAM, as observed for other members of the Radical SAM family by ENDOR.

The phosphatidylserine receptor has essential functions during embryogenesis but not in apoptotic cell removal.

Background: Phagocytosis of apoptotic cells is fundamental to animal development, immune function and cellular homeostasis. The phosphatidylserine receptor (Ptdsr) on phagocytes has been implicated in the recognition and engulfment of apoptotic cells and in anti-inflammatory signaling. To determine the biological function of the phosphatidylserine receptor in vivo, we inactivated the Ptdsr gene in the mouse.

Adhesins and invasins of pathogenic bacteria: a structural view.

Adhesion and invasion of pathogenic bacteria represent the important initial step of infection. Pathogens utilize surface-located adhesins/invasins for specific interaction with host cell receptors. The three-dimensional structures of a number of adhesins/invasins show that many are elongated molecules containing domains commonly found in eukaryotic proteins.

Taxonomy of the glycerol fermenting clostridia and description of Clostridium diolis sp. nov.

Six Clostridium strains which ferment glycerol to 1,3-propanediol were tested for their taxonomic and phylogenetic relatedness. All but one were known as C butyricum. By physiological tests, 16S rDNA sequences and fatty acid composition two groups were distinguished.

Structure of internalin, a major invasion protein of Listeria monocytogenes, in complex with its human receptor E-cadherin.

Listeria monocytogenes, a food-borne bacterial pathogen, enters mammalian cells by inducing its own phagocytosis. The listerial protein internalin (InlA) mediates bacterial adhesion and invasion of epithelial cells in the human intestine through specific interaction with its host cell receptor E-cadherin. We present the crystal structures of the functional domain of InlA alone and in a complex with the extracellular, N-terminal domain of human E-cadherin (hEC1).

Transformation of chlorinated benzenes and toluenes by Ralstonia sp. strain PS12 tecA (tetrachlorobenzene dioxygenase) and tecB (chlorobenzene dihydrodiol dehydrogenase) gene products.

The tecB gene, located downstream of tecA and encoding tetrachlorobenzene dioxygenase, in Ralstonia sp. strain PS12 was cloned into Escherichia coli DH5alpha together with the tecA gene. The identity of the tecB gene product as a chlorobenzene dihydrodiol dehydrogenase was verified by transformation into the respective catechols of chlorobenzene, the three isomeric dichlorobenzenes, as well as 1,2,3- and 1,2,4-trichlorobenzenes, all of which are transformed by TecA into the respective dihydrodihydroxy derivatives.

ActA from Listeria monocytogenes can interact with up to four Ena/VASP homology 1 domains simultaneously.

The facultative intracellular human pathogenic bacterium Listeria monocytogenes actively recruits host actin to its surface to achieve motility within infected cells. The bacterial surface protein ActA is solely responsible for this process by mimicking fundamental steps of host cell actin dynamics. ActA, a modular protein, contains an N-terminal actin nucleation site and a central proline-rich motif of the 4-fold repeated consensus sequence FPPPP (FP(4)).