AurF from Streptomyces thioluteus and a Possible New Family of Manganese/Iron Oxygenases

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• 作者：Carsten Krebs ; Megan L. Matthews ; Wei Jiang ; J. Martin Bollinger ; Jr.
• 刊名：Biochemistry
• 出版年：2007
• 出版时间：September 18, 2007
• 年：2007
• 卷：46
• 期：37
• 页码：10413 - 10418
• 全文大小：287K
• 年卷期：v.46,no.37(September 18, 2007)
• ISSN：1520-4995

文摘

We recently reported that the R2 subunit of class Ic ribonucleotide reductase from Chlamydiatrachomatis contains a heterodinuclear Mn/Fe redox cofactor [Jiang, W., Yun, D., Saleh, L., Barr, E. W.,Xing, G., Hoffart, L. M., Maslak, M.-A., Krebs, C., and Bollinger, J. M., Jr. (2007) Science 316, 1188-1191]. The N-oxygenase, AurF, from Streptomyces thioluteus catalyzes the six-electron oxidation ofp-aminobenzoate to p-nitrobenzoate and contains the EX₂HX_60-180EX₂H sequence motif previously usedto identify proteins with non-heme diiron clusters. Two research groups independently obtained evidencefor the presence of iron and manganese in preparations of AurF. The electron paramagnetic resonance(EPR) spectrum of purified, resting AurF presented in one of these studies is markedly similar to thespectrum of the Mn^III/Fe^III form of C. trachomatis R2. We propose that S. thioluteus AurF also mayharbor a heterodinuclear Mn/Fe cofactor, which it may use to activate O₂ for oxidation of the aryl amineto the nitro compound. Hypothetical proteins encoded in the genomes of several other bacteria have similarsequences and may also be members of this nascent family of oxygen-activating Mn/Fe proteins.