Question

Which of the following statements about COG is incorrect regarding its features?

(a) Currently, there are 4,873 clusters in the COG databases derived from unicellular organisms

(b) It is constructed by comparing protein sequences encoded in forty-three completely sequenced genomes, which are mainly from prokaryotes, representing thirty major phylogenetic lineages

(c) The interface for sequence searching in the COG database is the COGnitor program, which is based on gapped BLAST

(d) It is a protein family database based on structural classification

The question was asked in unit test.

The question is from Protein Family Databases in division Sequence Alignment of Bioinformatics

Answer 1

The correct option is (d) It is a protein family database based on structural classification

The explanation is: COG which stands for Cluster of Orthologous Groups, is a protein family database based on phylogenetic classification. Because orthologous proteins shared by three or more lineages are considered to have descended through a vertical evolutionary scenario, if the function of one of the members is known, functionality of other members can be assigned.