TY - JOUR
T1 - Metal-free class Ie ribonucleotide reductase from pathogens initiates catalysis with a tyrosinederived dihydroxyphenylalanine radical
AU - Blaesi, Elizabeth J.
AU - Palowitch, Gavin M.
AU - Hu, Kai
AU - Kim, Amelia J.
AU - Rose, Hannah R.
AU - Alapati, Rahul
AU - Lougee, Marshall G.
AU - Kim, Hee Jong
AU - Taguchi, Alexander T.
AU - Tan, Kong Ooi
AU - Laremore, Tatiana N.
AU - Griffin, Robert G.
AU - Krebs, Carsten
AU - Matthews, Megan L.
AU - Silakov, Alexey
AU - Bollinger, J. Martin
AU - Allen, Benjamin D.
AU - Boal, Amie K.
N1 - Funding Information:
ACKNOWLEDGMENTS. We thank JoAnne Stubbe for donation of N3-CDP and Benjamin Garcia and his group for instrument time and helpful discussions. Support was provided by grants from the Searle Scholars Program (to A.K.B.) and National Institutes of Health (NIH) Grant GM119707 (to A.K.B.). E.J.B. was supported by NIH Ruth L. Kirschstein Postdoctoral National Research Service Award GM116353. Portions of this work were performed at the Penn State Proteomics and Mass Spectrometry Core Facility and at the Advanced Photon Source (APS), the latter a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357. GM/CA at APS has been funded in whole or in part with federal funds from the National Cancer Institute (ACB-12002) and the National Institute of General Medical Sciences (AGM-12006). The Eiger 16M detector was funded by NIH Office of Research Infrastructure Programs High-End Instrumentation Grant 1S10OD012289-01A1. The use of LS-CAT Sector 21 was supported by Michigan Economic Development Corporation and Michigan Technology Tri-Corridor Grant 085P1000817.
Publisher Copyright:
© 2018 National Academy of Sciences. All rights reserved.
PY - 2018/10/2
Y1 - 2018/10/2
N2 - All cells obtain 2′-deoxyribonucleotides for DNA synthesis through the activity of a ribonucleotide reductase (RNR). The class I RNRs found in humans and pathogenic bacteria differ in (i) use of Fe(II), Mn(II), or both for activation of the dinuclear-metallocofactor subunit, β; (ii) reaction of the reduced dimetal center with dioxygen or superoxide for this activation; (iii) requirement (or lack thereof) for a flavoprotein activase, NrdI, to provide the superoxide from O2; and (iv) use of either a stable tyrosyl radical or a high-valent dimetal cluster to initiate each turnover by oxidizing a cysteine residue in the α subunit to a radical (Cys•). The use of manganese by bacterial class I, subclass b-d RNRs, which contrasts with the exclusive use of iron by the eukaryotic Ia enzymes, appears to be a countermeasure of certain pathogens against iron deprivation imposed by their hosts. Here, we report a metal-free type of class I RNR (subclass e) from two human pathogens. The Cys• in its α subunit is generated by a stable, tyrosine-derived dihydroxyphenylalanine radical (DOPA•) in β. The three-electron oxidation producing DOPA• occurs in Escherichia coli only if the β is coexpressed with the NrdI activase encoded adjacently in the pathogen genome. The independence of this new RNR from transition metals, or the requirement for a single metal ion only transiently for activation, may afford the pathogens an even more potent countermeasure against transition metal-directed innate immunity.
AB - All cells obtain 2′-deoxyribonucleotides for DNA synthesis through the activity of a ribonucleotide reductase (RNR). The class I RNRs found in humans and pathogenic bacteria differ in (i) use of Fe(II), Mn(II), or both for activation of the dinuclear-metallocofactor subunit, β; (ii) reaction of the reduced dimetal center with dioxygen or superoxide for this activation; (iii) requirement (or lack thereof) for a flavoprotein activase, NrdI, to provide the superoxide from O2; and (iv) use of either a stable tyrosyl radical or a high-valent dimetal cluster to initiate each turnover by oxidizing a cysteine residue in the α subunit to a radical (Cys•). The use of manganese by bacterial class I, subclass b-d RNRs, which contrasts with the exclusive use of iron by the eukaryotic Ia enzymes, appears to be a countermeasure of certain pathogens against iron deprivation imposed by their hosts. Here, we report a metal-free type of class I RNR (subclass e) from two human pathogens. The Cys• in its α subunit is generated by a stable, tyrosine-derived dihydroxyphenylalanine radical (DOPA•) in β. The three-electron oxidation producing DOPA• occurs in Escherichia coli only if the β is coexpressed with the NrdI activase encoded adjacently in the pathogen genome. The independence of this new RNR from transition metals, or the requirement for a single metal ion only transiently for activation, may afford the pathogens an even more potent countermeasure against transition metal-directed innate immunity.
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U2 - 10.1073/pnas.1811993115
DO - 10.1073/pnas.1811993115
M3 - Article
C2 - 30224458
AN - SCOPUS:85054393678
VL - 115
SP - 10022
EP - 10027
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 40
ER -