superhelix
/ˈsuːpəhiːlɪks
/noun (plural superhelices) Biochemistry
A helical structure formed from a number of protein or nucleic acid chains which are individually helical.The crystal structure reveals a novel supercoil structure in which four parallel WAT chains form a left-handed superhelix around an antiparallel left-handed proline rich attachment domain helix resembling polyproline II....
- Consequently, they proposed a compact structural motif for the entire peptide in which the [beta] sheet structure of the superhelix is a sheet with three strands connected by two turns.
- Apart from its effect on the molecular free energy, the topological constraint determines the total length and diameter of the superhelix, and hence, the volume excluded to another supercoil.
Derivatives
superhelical
- Its major biological role in the bacterial cell is the removal of excessive negative supercoils from DNA to maintain the DNA at optimal superhelical density along with DNA gyrase.
- Based on our previous work on superhelical DNA and polynucleosomes, it reintegrates aspects of the ‘solenoid’ and the ‘zig-zag’ models.
- Intriguingly, experiments show clear differences in the dependence of the formation of paired hix sites and of the formation of the invertasome on the superhelical density [sigma] of the DNA substrate.