Question

Which of these are major structural classifications of DNA-binding domains that are found in eukaryotic transcription factors?

A. helix-turn-helix
B. leucine zipper
C. zinc finger

Answer 1

The major structural classifications of DNA-binding domains in eukaryotic transcription factors are helix-turn-helix, leucine zipper, and zinc finger.

Step-by-step explanation:

The major structural classifications of DNA-binding domains in eukaryotic transcription factors are:

1. Helix-turn-helix (HTH): This domain consists of two α-helices joined by a loop, and it is frequently found in transcription factors that bind DNA in a sequence-specific manner.
2. Leucine zipper: This domain is composed of leucine residues that form a coiled-coil structure, allowing transcription factors to dimerize and bind DNA.
3. Zinc finger: This domain contains a conserved structure formed by cysteine and/or histidine residues coordinated with zinc ions, enabling DNA binding.