Bacterial cell division depends on the formation of a cytokinetic ring structure, the Z-ring. The bacterial tubulin homologue FtsZ is required for Z-ring formation. FtsZ assembles into various polymeric forms in vitro, indicating a structural role in the septum of bacteria. We have used recombinant FtsZ1 protein from M. jannaschii to produce helical tubes and sheets with high yield using the GT...

Coiled coils are highly represented in biologically relevant macromolecules involved in important biological functions, such as gene expression regulation. The coiled coil environment has the great advantage to provide two very well defined intermolecular recognition surfaces. The peptide system VPE-VPK is a rationally designed heterodimeric coiled coil structure [1,2]. The characteristic struc...

The special problems of preparing suspensions of cell fractions such as mitochondria for electron microscopy are largely eliminated once the fixed organclles are gathered into a cohesive pellet. Thesc pellets may then be handled in the manner conventional for blocks of tissue (1, 2). The use of very small samples (e.g., the mitochondrial yield from 4 mg of rat liver) has been made possible by t...

Viscothermal acoustic propagation in gases contained rigid straight or conical tubes is considered. Under the assumption that wavelength much larger than both boundary layer thickness and tube radius, pressure flow are shown to be solutions of a pair coupled 1D differential equations, formulated as transmission line equations involving complex loss coefficients. The derivation these coefficient...

A peptide-based electron-transfer system has been designed in which the specific positions of redox-active metal complexes appended to either an alpha-helix, or an alpha-helical coiled-coil, can be reversed to test the effect of the helix dipole in controlling photoinduced electron-transfer rates. Two 30-residue apopeptides were prepared having the following sequences: (I) Ac-K-(IEALEGK)(ICALEG...