1R6Y

Crystal structure of YgiN from Escherichia coli

Summary for 1R6Y

• Entry DOI: 10.2210/pdb1r6y/pdb
• Descriptor: Protein ygiN (2 entities in total)
• Functional Keywords: structural genomics, hypothetical protein, functional annotation, ferredoxin-like fold, montreal-kingston bacterial structural genomics initiative, bsgi, unknown function
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 12904.83

Authors

Adams, M.A.,Jia, Z.,Montreal-Kingston Bacterial Structural Genomics Initiative (BSGI) (deposition date: 2003-10-17, release date: 2004-11-02, Last modification date: 2024-02-14)

Primary citation

Adams, M.A.,Jia, Z.
Structural and biochemical evidence for an enzymatic quinone redox cycle in Escherichia coli: identification of a novel quinol monooxygenase.
J.Biol.Chem., 280:8358-8363, 2005

PubMed Abstract: Naturally synthesized quinones perform a variety of important cellular functions. Escherichia coli produce both ubiquinone and menaquinone, which are involved in electron transport. However, semiquinone intermediates produced during the one-electron reduction of these compounds, as well as through auto-oxidation of the hydroxyquinone product, generate reactive oxygen species that stress the cell. Here, we present the crystal structure of YgiN, a protein of hitherto unknown function. The three-dimensional fold of YgiN is similar to that of ActVA-Orf6 monooxygenase, which acts on hydroxyquinone substrates. YgiN shares a promoter with "modulator of drug activity B," a protein with activity similar to that of mammalian DT-diaphorase capable of reducing mendione. YgiN was able to reoxidize menadiol, the product of the "modulator of drug activity B" (MdaB) enzymatic reaction. We therefore refer to YgiN as quinol monooxygenase. Modulator of drug activity B is reported to be involved in the protection of cells from reactive oxygen species formed during single electron oxidation and reduction reactions. The enzymatic activities, together with the structural characterization of YgiN, lend evidence to the possible existence of a novel quinone redox cycle in E. coli.

PubMed: 15613473
DOI: 10.1074/jbc.M412637200

Experimental method

X-RAY DIFFRACTION (2.2 Å)