Quarterly Reviews of Biophysics - Current Issue

Volume 41 Issue 02

Wed, 30 Apr 2008 23:00:00 GMT

Quarterly Reviews of Biophysics, Volume 41 Issue 02

Quarterly Reviews of Biophysics covers the whole field of biophysics, from ion channels to DNA topology and from X-ray diffraction to NMR. The journal has gained a worldwide reputation, demonstrated by its high ranking in the ISI Science Citation Index, as a forum for general and specialised communication between biophysicists working in different areas. The majority of reviews published are invited from authors who have made significant contributions to the field, who give critical, readable and sometimes controversial accounts of recent progress and problems in their speciality. Thematic issues are occasionally published.

Bacterial flagellar motor

Review Articles
Yoshiyuki Sowa, Richard M. Berry,
Quarterly Reviews of Biophysics, Volume 41 Issue 02 , pp 103-132

Abstract
The bacterial flagellar motor is a reversible rotary nano-machine, about 45 nm in diameter, embedded in the bacterial cell envelope. It is powered by the flux of H+ or Na+ ions across the cytoplasmic membrane driven by an electrochemical gradient, the proton-motive force or the sodium-motive force. Each motor rotates a helical filament at several hundreds of revolutions per second (hertz). In many species, the motor switches direction stochastically, with the switching rates controlled by a network of sensory and signalling proteins. The bacterial flagellar motor was confirmed as a rotary motor in the early 1970s, the first direct observation of the function of a single molecular motor. However, because of the large size and complexity of the motor, much remains to be discovered, in particular, the structural details of the torque-generating mechanism. This review outlines what has been learned about the structure and function of the motor using a combination of genetics, single-molecule and biophysical techniques, with a focus on recent results and single-molecule techniques.

Protein–protein interaction and quaternary structure

Review Articles
Joël Janin, Ranjit P. Bahadur, Pinak Chakrabarti,
Quarterly Reviews of Biophysics, Volume 41 Issue 02 , pp 133-180

Abstract
Protein protein complexes, oligomeric proteins, viral capsids and protein nucleic acid complexes. These biologically significant interfaces are generally close-packed, whereas the non-specific interfaces between molecules in protein crystals are loosely packed, an observation that gives a structural basis to specific recognition. A distinction is made within each interface between a core that contains buried atoms and a solvent accessible rim. The core and the rim differ in their amino acid composition and their conservation in evolution, and the distinction helps correlating the structural data with the results of site-directed mutagenesis and in vitro studies of self-assembly.