The C6 zinc cluster dictates asymmetric binding by HAP1.
Unlike other C6 zinc cluster proteins such as GAL4 and PPR1, HAP1 binds selectively to asymmetric DNA sites containing a direct repeat of two CGG triplets. Here, we show that the HAP1 zinc cluster is solely responsible for asymmetric binding by HAP1. An asymmetric interaction between two zinc clusters of a HAP1 dimer must position the zinc clusters in a directly repeated orientation, and enable them to recognize two CGG triplets in a direct repeat. Further, our data suggest that this asymmetric interaction acts cooperatively with the interaction between dimerization elements to promote HAP1 dimerization, and locks HAP1-DNA complexes in a stable, dimeric conformation.
Department of Biochemistry, NYU Medical Center, New York 10016, USA.
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D001704:Biopolymers; D019757:Carbon-Oxygen Lyases; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D004268:DNA-Binding Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D011485:Protein Binding; D015032:Zinc / Q000378:metabolism*
D001704:Biopolymers; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D019757:Carbon-Oxygen Lyases; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D015032:Zinc