Ribonucleotide reductase EXAFS

Figure 3. First shell (1.1-2.3A) EXAFS spectra of methemerythrin azide, semimethemerythrin azide, ribonucleotide reductase B2 subunit, oxidized uteroferrin-phosphate complex, and reduced uteroferrin.

For hemerythrin and ribonucleotide reductase, resonance Raman and EXAFS spectroscopy provide clear evidence for an oxo bridge (31-33,43,45, 62,63,65-67). Surprisingly, such evidence is lacking for the oxidized acid phosphatases. The VFe-o-Fe feature expected at ca. 500 cm has not been observed... 

Riggs-Gelasco, P. J., Shu, L. J., Chen, S. X., Burdi, D., Huynh, B. H., Que, L., and Stubbe, J., 1998, Exafs Characterization of the intermediate X generated during the assembly of the Escherichia coli ribonucleotide reductase R2 diferric tyrosyl radical cofactor, J. Am. Chem. Soc. 120 8499860. 

ACP = acyl carrier protein ACPA D = ACPA desat-urase AlkB = octane 1-monooxygenase AOX = alternative oxidase DMQ hydroxylase = 5-demethoxyquinone hydroxylase EXAFS = extended X-ray absorption fine structure spectroscopy FMN = flavin mononucleotide FprA = flavoprotein A (flavo-diiron enzyme homologue) Hr = hemerythrin MCD = magnetic circular dichroism MME hydroxylase = Mg-protophorphyrin IX monomethyl ester hydroxylase MMO = methane monooxygenase MMOH = hydroxylase component of MMO NADH = reduced nicotinamide adenine dinucleotide PAPs = purple acid phosphatases PCET = proton-coupled electron transfer, PTOX = plastid terminal oxidase R2 = ribonucleotide reductase R2 subunit Rbr = rubrerythrin RFQ = rapid freeze-quench RNR = ribonucleotide reductase ROO = rubredoxin oxygen oxidoreductase XylM = xylene monooxygenase. 

Scarrow RC, Maroney MJ, Palmer SM, Que Jr L, Roe AL, Salowe SP, Stubbe J. 1987. EXAFS studies of binuclear iron proteins hemerythrin and ribonucleotide reductase. J Am Chem Soc 109 7857-7864. 

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