Question

Which of the following is true regarding Coiled coil?

(a) They have an integral repeat of twenty residues

(b) They have an integral repeat of seven residues

(c) They have an integral repeat of thirty residues

(d) The sequence periodicity doesn’t contribute in designing algorithms to predict the structural domain.

The question was asked in final exam.

This intriguing question originated from Coiled Coil Prediction in portion Secondary Structure Prediction of Bioinformatics

Answer 1

The correct choice is (b) They have an integral repeat of seven residues

The explanation is: Coiled coils have an integral repeat of seven residues (heptads) which assume a side-chain packing geometry at facing residues. For every seven residues, the first and fourth are hydrophobic, facing the helical interface; the others are hydrophilic and exposed to the solvent. The sequence periodicity forms the basis for designing algorithms to predict this important structural domain.