3DH8

Structure of Pseudomonas Quinolone Signal Response Protein PqsE

3DH8 の概要

• エントリーDOI: 10.2210/pdb3dh8/pdb
• 関連するPDBエントリー: 2Q0I 2Q0J
• 分子名称: Uncharacterized protein PA1000, FE (III) ION, bis(4-nitrophenyl) hydrogen phosphate, ... (4 entities in total)
• 機能のキーワード: quorum sensing, pseudomonas quinolone signal, pqs, metal-beta-lactamase, iron, phosphodiesterase, metal binding protein
• 由来する生物種: Pseudomonas aeruginosa
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 34969.36

構造登録者

Yu, S.,Blankenfeldt, W. (登録日: 2008-06-17, 公開日: 2009-06-23, 最終更新日: 2023-11-01)

主引用文献

Yu, S.,Jensen, V.,Seeliger, J.,Feldmann, I.,Weber, S.,Schleicher, E.,Haussler, S.,Blankenfeldt, W.
Structure elucidation and preliminary assessment of hydrolase activity of PqsE, the Pseudomonas quinolone signal (PQS) response protein.
Biochemistry, 48:10298-10307, 2009

PubMed Abstract: In bacteria, the transcription of virulence genes is usually controlled by a cell density-dependent process known as "quorum sensing" (QS). QS relies on small diffusible signaling molecules that cross the bacterial cell wall and activate target transcription factors after a threshold concentration has been reached. Besides two hierarchical QS circuits based on N-acylhomoserine lactones, the human opportunistic pathogen Pseudomonas aeruginosa integrates a signaling system that depends on 2-heptyl-3-hydroxy-4-quinolone, termed "Pseudomonas quinolone signal" (PQS). PQS is produced from genes encoded in the pqs operon, which in addition to the biosynthetic enzymes PqsA-D contains a fifth gene, pqsE, that is not required for production of PQS but whose disruption leads to loss of signal transduction in several but not all pqs operon-dependent processes. PqsE was hence termed "PQS response protein", but its exact mechanism of action is unknown. We have determined the crystal structure of recombinant PqsE and show that it possesses a metallo-beta-lactamase fold with an Fe(II)Fe(III) center in the active site. A copurified ligand was assigned as benzoate and may indicate that PqsE exerts its regulatory effect by converting a chorismate-derived molecule. Further, PqsE was found to slowly hydrolyze phosphodiesters including single- and double-stranded DNA as well as mRNA and also the thioester S-(4-nitrobenzoyl)mercaptoethane. Higher activity was observed after incubation with Co(2+) and, to lesser entent, Mn(2+), suggesting that the Fe(II)Fe(III) center of recombinant PqsE may be an artifact of heterologous expression. A crystal complex of the E182A mutant with bis-pNPP was obtained and suggests a catalytic mechanism for hydrolysis.

PubMed: 19788310
DOI: 10.1021/bi900123j

実験手法

X-RAY DIFFRACTION (1.8 Å)