4Z85

Crystal structur of Pseudomonas fluorescens 2-nitrobenzoate 2-nitroreductase NbaA

4Z85 の概要

• エントリーDOI: 10.2210/pdb4z85/pdb
• 分子名称: 2-nitrobenzoate nitroreductase (2 entities in total)
• 機能のキーワード: 2-nitrobenzoate 2-nitroreductase (nbaa), 2-nitrobenzoate methyl ester, fmn-binding site, tyrosine modification, cysteine reactivity, oxidoreductase
• 由来する生物種: Pseudomonas fluorescens
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 24437.93

構造登録者

Ha, N.C.,Jiao, L.,Kim, J.S. (登録日: 2015-04-08, 公開日: 2016-01-20, 最終更新日: 2023-11-08)

主引用文献

Kim, Y.H.,Song, W.,Kim, J.S.,Jiao, L.,Lee, K.,Ha, N.C.
Structural and Mechanistic Insights into the Pseudomonas fluorescens 2-Nitrobenzoate 2-Nitroreductase NbaA
Appl.Environ.Microbiol., 81:5266-5277, 2015

PubMed Abstract: The bacterial 2-nitroreductase NbaA is the primary enzyme initiating the degradation of 2-nitrobenzoate (2-NBA), and its activity is controlled by posttranslational modifications. To date, the structure of NbaA remains to be elucidated. In this study, the crystal structure of a Cys194Ala NbaA mutant was determined to a 1.7-Å resolution. The substrate analog 2-NBA methyl ester was used to decipher the substrate binding site by inhibition of the wild-type NbaA protein. Tandem mass spectrometry showed that 2-NBA methyl ester produced a 2-NBA ester bond at the Tyr193 residue in the wild-type NbaA but not residues in the Tyr193Phe mutant. Moreover, covalent binding of the 2-NBA methyl ester to Tyr193 reduced the reactivity of the Cys194 residue on the peptide link. The Tyr193 hydroxyl group was shown to be essential for enzyme catalysis, as a Tyr193Phe mutant resulted in fast dissociation of flavin mononucleotide (FMN) from the protein with the reduced reactivity of Cys194. FMN binding to NbaA varied with solution NaCl concentration, which was related to the catalytic activity but not to cysteine reactivity. These observations suggest that the Cys194 reactivity is negatively affected by a posttranslational modification of the adjacent Tyr193 residue, which interacts with FMN and the substrate in the NbaA catalytic site.

PubMed: 26025888
DOI: 10.1128/AEM.01289-15

実験手法

X-RAY DIFFRACTION (1.7 Å)