3BTC

crystal structure of QacR(E57Q) bound to malachite green

3BTC の概要

• エントリーDOI: 10.2210/pdb3btc/pdb
• 関連するPDBエントリー: 1jt6 1jty 1jum 1jup 1jus 1qvt 3BT9 3BTI 3BTJ
• 分子名称: HTH-type transcriptional regulator qacR, SULFATE ION, MALACHITE GREEN, ... (4 entities in total)
• 機能のキーワード: qacr, multidrug binding, malachite green, dye, dna-binding, plasmid, repressor, transcription, transcription regulation
• 由来する生物種: Staphylococcus aureus subsp. aureus Mu50
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 90479.09

構造登録者

Schumacher, M.A.,Schuman, J.T.,Brennan, R.G. (登録日: 2007-12-28, 公開日: 2008-08-12, 最終更新日: 2023-08-30)

主引用文献

Peters, K.M.,Schuman, J.T.,Skurray, R.A.,Brown, M.H.,Brennan, R.G.,Schumacher, M.A.
QacR-cation recognition is mediated by a redundancy of residues capable of charge neutralization
Biochemistry, 47:8122-8129, 2008

PubMed Abstract: The Staphylococcus aureus multidrug binding protein QacR binds to a broad spectrum of structurally dissimilar cationic, lipophilic drugs. Our previous structural analyses suggested that five QacR glutamic acid residues are critical for charge neutralization and specification of certain drugs. For example, E57 and E58 interact with berberine and with one of the positively charged moieties of the bivalent drug dequalinium. Here we report the structural and biochemical effects of substituting E57 and E58 with alanine and glutamine. Unexpectedly, individual substitutions of these residues did not significantly affect QacR drug binding affinity. Structures of QacR(E57Q) and QacR(E58Q) bound to dequalinium indicated that E57 and E58 are redundant for charge neutralization. The most significant finding was that berberine was reoriented in the QacR multidrug binding pocket so that its positive charge was neutralized by side chain oxygen atoms and aromatic residues. Together, these data emphasize the remarkable versatility of the QacR multidrug binding pocket, illustrating that the capacity of QacR to bind myriad cationic drugs is largely governed by the presence in the pocket of a redundancy of polar, charged, and aromatic residues that are capable of electrostatic neutralization.

PubMed: 18616285
DOI: 10.1021/bi8008246

実験手法

X-RAY DIFFRACTION (2.9 Å)