Structure of DNA helicase RepA in complex with sulfate at 1.95 A resolution implicates structural changes to an "open" form.

The structure of a new crystal form (space group C2), grown at pH 8.0 and diffracting to 1.95 A resolution, of the replicative homo-hexameric DNA helicase RepA encoded by plasmid RSF1010 is reported.

The 3D structure of rat DPPIV/CD26 as obtained by cryo-TEM and single particle analysis.

We present the three-dimensional structure of rat DPPIV/CD26, as determined by cryo-TEM and single particle analysis at a resolution of approximately 14A. The reconstruction confirms that the protein exists as a dimer, as predicted earlier. Since there are structural analogies to the serine peptidase POP, docking calculations of the two structures were performed.

A multidisciplinary team approach to preservation of quality of life for patients following oral cancer surgery.

Knowledge of the etiology and pathophysiology of, and risk factors contributing to oral cavity cancer facilitates patient assessment and diagnosis. If untreated, oral cavity cancer can be disabling and potentially fatal. Even when treated, using the modalities discussed in this article, the patient experiences significant changes in body image and quality of life.

Chiral J-aggregates formed by achiral cyanine dyes.

The self-assembly of helical supramolecular structures from chiral building units is a basic principle of biological materials. The mesoscopic structure of a chiral molecular aggregate, which formed spontaneously from a nonchiral J-aggregating cyanine dye in aqueous solution, is presented. In single crystals (as shown in the picture) a coexistance of planar molecules with left- and right-handed twisted conformers of the same dye are found; the latter may act as templates to build up the helical superstructures.

Structure of influenza haemagglutinin at neutral and at fusogenic pH by electron cryo-microscopy.

The three-dimensional structures of the complete haemagglutinin (HA) of influenza virus A/Japan/305/57 (H2N2) in its native (neutral pH) and membrane fusion-competent (low pH) form by electron cryo-microscopy at a resolution of 10 A and 14 A, respectively, have been determined. In the fusion-competent form the subunits remain closely associated preserving typical overall features of the trimeric ectodomain at neutral pH. Rearrangements of the tertiary structure in the distal and the stem parts are associated with the formation of a central cavity through the entire ectodomain.

Topogenesis of a microsomal cytochrome P450 and induction of endoplasmic reticulum membrane proliferation in Saccharomyces cerevisiae.

Cytochrome P450 52A3 (P450Cm1) is one of the membrane proteins known to trigger by its high-level expression a marked proliferation of the endoplasmic reticulum, (ER). To gain insight into the relationship between the expression of a membrane protein and the induction of ER proliferation we have characterized the membrane topology of P450Cm1 and identified the structural determinants required for ER targeting, formation of correct membrane orientation, and ER retention. We show that all these features are interrelated and determined by sequence elements within the NH2-terminal region of P450Cm1.