Conserved Residues Make Similar Contacts in Two Repressor-Operator Complexes

作者：Carl O. Pabo, Aneel K. Aggarwal, Steven R. Jordan, Lesa J. Beamer, Upul Obeysekare, Stephen C. Harrison · 发表于：Science · 年份：1990 · DOI：10.1126/science.2315694 · 被引用次数：100 · 研究领域：Chemical Synthesis and Analysis、Protein Structure and Dynamics、Enzyme Structure and Function

Comparison of a lambda repressor-operator complex and a 434 repressor-operator complex reveals that three conserved residues in the helix-turn-helix (HTH) region make similar contacts in each of the crystallographically determined structures. These conserved residues and their interactions with phosphodiester oxygens help establish a frame of reference within which other HTH residues make contacts that are critical for site-specific recognition. Such "positioning contacts" may be important conserved features within families of HTH proteins. In contrast, the structural comparisons appear to rule out any simple "recognition code" at the level of detailed side chain-base pair interactions.