The DNA-binding domain of nuclear receptors (such as the glucocorticoid receptor) contains which structural motif that directly contacts the major groove of DNA at hormone response elements?

• A Leucine zipper
• B Zinc finger ✓
• C Helix-loop-helix
• D Homeodomain

Explanation

Nuclear receptors contain two zinc finger motifs in their DNA-binding domain, each stabilized by four cysteine residues coordinating a zinc ion. The first zinc finger determines DNA sequence specificity for the hormone response element, while the second stabilizes DNA binding. Leucine zippers are found in bZIP transcription factors, helix-loop-helix in Myc/Max, and homeodomains in developmental regulators.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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