The HDQVH-motif in domain E of the estradiol receptor alpha is responsible for zinc-binding and zinc-induced hormone release.
The estradiol receptor alpha and proteolytic fragments thereof which contain the entire ligand-binding domain E, bind 65Zn with high affinity. Four putative double-histidine zinc-binding sequences can be identified within the hormone-binding domain E: HDQVH [amino acid (aa) 373-377], HIH (aa 474-476), HFRH (aa 513-516) and HRLH (aa 547-550). Only the HDQVH-motif is responsible for the 1:1 zinc-binding to domain E because the proteolytic (endo-Lys-C) 17 kDa fragment (aa 303-467) from porcine estradiol receptor alpha possesses the zinc-binding ability but none of the fragments containing the other motifs. In addition, H373A- and H377A-mutants lack the metal-binding capacity. Moreover, divalent metal ions are able to release estradiol out of the binding-niche. The order for this feature parallels the competition pattern of 65Zn-binding: Mg2+ < Ni2+ << Zn2+ < or = Cu2+. Mutant estradiol receptor alpha fragments (H373A and H377A) lack the zinc-induced hormone release.
Humeny
A
A
Max-Planck-Institut für Experimentelle Endokrinologie, Hannover, Germany.
Bökenkamp
D
D
Thole
H H
HH
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002413:Cations, Divalent; D003300:Copper / Q000494:pharmacology; D015246:Deoxyribonuclease EcoRI / Q000378:metabolism; D015247:Deoxyribonuclease HindIII / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D008666:Metalloendopeptidases / Q000378:metabolism; D016296:Mutagenesis; D009532:Nickel / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011959:Receptors, Estradiol / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship; D013552:Swine; D014316:Tritium; D015032:Zinc / Q000378:metabolism* / Q000494:pharmacology*
D002413:Cations, Divalent; D010446:Peptide Fragments; D011959:Receptors, Estradiol; D011994:Recombinant Proteins; D014316:Tritium; D004958:Estradiol; D003300:Copper; D009532:Nickel; D015246:Deoxyribonuclease EcoRI; D015247:Deoxyribonuclease HindIII; D008666:Metalloendopeptidases; C039830:peptidyl-Lys metalloendopeptidase; D015032:Zinc