Question

In the zinc finger, which residues in this sequence motif form ligands to a zinc ion?

(a) Cysteine and histidine

(b) Cysteine and arginine

(c) Histidine and proline

(d) Histidine and arginine

The question was asked during an internship interview.

This is a very interesting question from Protein Motifs and Domain Prediction in chapter Sequence Alignment of Bioinformatics

Answer 1

Right option is (a) Cysteine and histidine

To explain: In the zinc finger, which is found in a widely varying family of DNA-binding proteins, cysteine and histidine residues in this sequence motif form ligands to a zinc ion whose coordination is essential to stabilize the tertiary structure.