Functional interference between contacting amino acids of homeodomains

FEBS Letters

Tell, Gianluca¹  Pucillo, Carlo¹  Damante, Giuseppe¹  Pellizzari, Lucia¹  Fabbro, Dora¹ 

[1] Dipartimento di Scienze e Tecnologie Biomediche, Università di Udine, P. le Kolbe 1, 33100 Udine, Italy

关键词: DNA binding;    Homeodomain;    Amino acid;   

DOI  :  10.1016/S0014-5793(97)00368-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In a protein, the function of an amino acid at some position depends on the amino acids at other positions. Here we demonstrate a functional interference between base-contacting amino acids (at positions 50 and 54) of homeodomains. When, in the context of Antennapedia or Goosecoid homeodomains, Lys⁵⁰ is paired to Tyr⁵⁴ or Ala⁵⁴ and Gln⁵⁰ is paired to Met⁵⁴, the resulting proteins efficiently discriminate among different DNA sequences. In contrast, in the presence of the pair Lys⁵⁰-Met⁵⁴, both homeodomains show a reduced capability to discriminate among different DNA sequences. Sequence selection experiments performed in the context of the Goosecoid homeodomain suggest that the presence of Met⁵⁴ precludes the base-discriminating function of Lys⁵⁰. These results may explain why the pair Lys⁵⁰-Met⁵⁴ is never found in natural homeodomains.

【 授权许可】

Unknown