Question

Which of the following is untrue about 3D-PSSM?

(a) It is a web-based program that employs the structural profile method to identify protein folds

(b) The profiles for each protein superfamily are constructed by combining multiple smaller profiles

(c) A protein structural superfamily doesn’t have sequence-based PSI-BLAST profile

(d) In initial steps, protein structures in a superfamily based on the SCOP classification are superimposed

I have been asked this question by my college professor while I was bunking the class.

Origin of the question is Threading and Fold Recognition topic in chapter Protein Tertiary Structure Prediction of Bioinformatics

Answer 1

Correct option is (c) A protein structural superfamily doesn’t have sequence-based PSI-BLAST profile

The explanation is: First, protein structures in a superfamily based on the SCOP classification are superimposed and are used to construct a structural profile by incorporating secondary structures and solvent accessibility information for corresponding residues. In addition, each member in a protein structural superfamily has its own sequence-based PSI-BLAST profile computed. These sequence profiles are used in combination with the structure profile to form a large superfamily profile in which each position contains both sequence and structural information.