AurF from Streptomyces thioluteus and a possible new family of manganese/iron oxygenases

作者：Krebs Carsten^*; Matthews Megan L; Jiang Wei; Bollinger J Martin Jr

来源：Biochemistry, 2007, 46(37): 10413-10418.

DOI：10.1021/bi701060g

We recently reported that the R2 subunit of class Ic ribonucleotide reductase from Chlamydia trachomatis 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 of p-aminobenzoate to p-nitrobenzoate and contains the EX2HX60-180EX2H sequence motif previously used to identify proteins with non-heme diiron clusters. Two research groups independently obtained evidence for the presence of iron and manganese in preparations of AurF. The electron paramagnetic resonance (EPR) spectrum of purified, resting AmF presented in one of these studies is markedly similar to the spectrum of the Mn-III/Fe-III form of C. trachomatis R2. We propose that S. thioluteus AurF also may harbor a heterodinuclear Mn/Fe cofactor, which it may use to activate O-2 for oxidation of the aryl amine to the nitro compound. Hypothetical proteins encoded in the genomes of several other bacteria have similar sequences and may also be members of this nascent family of oxygen-activating Mn/Fe proteins.

• 出版日期2007-9-18