1TY9

X-RAY CRYSTAL STRUCTURE OF PHZG FROM PSEUDOMONAS FLUORESCENS

1TY9 の概要

• エントリーDOI: 10.2210/pdb1ty9/pdb
• 関連するPDBエントリー: 1T9M
• 分子名称: Phenazine biosynthesis protein phzG, SULFATE ION, FLAVIN MONONUCLEOTIDE, ... (4 entities in total)
• 機能のキーワード: phenazine, phzg, chorismate, pseudomonas, oxidoreductase
• 由来する生物種: Pseudomonas fluorescens
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 51231.24

構造登録者

Parsons, J.F.,Eisenstein, E.,Ladner, J.E. (登録日: 2004-07-07, 公開日: 2004-11-23, 最終更新日: 2023-08-23)

主引用文献

Parsons, J.F.,Calabrese, K.,Eisenstein, E.,Ladner, J.E.
Structure of the phenazine biosynthesis enzyme PhzG.
Acta Crystallogr.,Sect.D, 60:2110-2113, 2004

PubMed Abstract: PhzG is a flavin-dependent oxidase that is believed to play a role in phenazine antibiotic synthesis in various bacteria, including Pseudomonas. Phenazines are chorismic acid derivatives that provide the producing organisms, including the opportunistic pathogen P. aeruginosa, with a competitive growth advantage. Here, the crystal structures of PhzG from both P. aeruginosa and P. fluorescens solved in an unliganded state at 1.9 and 1.8 A resolution, respectively, are described. Although the specific reaction in phenazine biosynthesis catalyzed by PhzG is unknown, the structural data indicates that PhzG is closely related to pyridoxine-5'-phosphate oxidase, the Escherichia coli pdxH gene product, which catalyzes the final step in pyridoxal-5'-phosphate (PLP) biosynthesis. A previous proposal suggested that the physiological substrate of PhzG to be 2,3-dihydro-3-hydroxyanthranilic acid (DHHA), a phenazine precursor produced by the sequential actions of the PhzE and PhzD enzymes on chorismate, and that two DHHA molecules dimerized in another enzyme-catalyzed reaction to yield phenazine-1-carboxylate. However, it was not possible to demonstrate any in vitro activity upon incubation of PhzG and DHHA. Interestingly, analysis of the in vitro activities of PhzG in combination with PhzF suggests that PhzF acts on DHHA and that PhzG then reacts with a non-aromatic tricyclic phenazine precusor to catalyze an oxidation/aromatization reaction that yields phenazine-1-carboxylate. It is proposed that phzG arose by duplication of pdxH and that the subtle differences seen between the structures of PhzG and PdxH correlate with the loss of the ability of PhzG to catalyze PLP formation. Sequence alignments and superimpositions of the active sites of PhzG and PdxH reveal that the residues that form a positively charged pocket around the phosphate of PLP in the PdxH-PLP complex are not conserved in PhzG, consistent with the inability of phosphorylated compounds to serve as substrates for PhzG.

PubMed: 15502343
DOI: 10.1107/S0907444904022474

実験手法

X-RAY DIFFRACTION (1.8 Å)