Quaternary structure of helical proteins with globular subunits

The quaternary structure of proteins composed of identical subunits.

SUMMARY The possible structures which could arise on assembly of identical subunits into oligomeric structures have been made by assuming (a) that these are closed structures, (b) that whatever conformational changes occur on association are the same for each subunit, and (c) that there is no a priori reason for preferring a particular type of binding domain. When such an analysis is applied to...

Conservation of Helical Bundle Structure between the Exocyst Subunits

BACKGROUND The exocyst is a large hetero-octomeric protein complex required for regulating the targeting and fusion of secretory vesicles to the plasma membrane in eukaryotic cells. Although the sequence identity between the eight different exocyst subunits is less than 10%, structures of domains of four of the subunits revealed a similar helical bundle topology. Characterization of several of ...

Quantification of structure/dynamics correlation of globular proteins

Glasslike structure of globular proteins and the boson peak.

Vibrational spectra of proteins and topologically disordered solids display a common anomaly at low frequencies, known as boson peak. We show that such feature in globular proteins can be deciphered in terms of an energy landscape picture, as it is for glassy systems. Exploiting the tools of Euclidean random matrix theory, we clarify the physical origin of such anomaly in terms of a mechanical ...

Automatic identification of secondary structure in globular proteins.

A computer program is used to analyse automatically and objectively the atomic co-ordinates of a large number of globular proteins in order to identify the regions of a-helix, p-sheet and reverse-turn secondary structure. Several different criteria for the assignment of secondary structure are tested for accuracy, reproducibility and efficiency. The most successful criterion, which is based on ...