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Article: Freeze-quench ⁵⁷Fe-Mössbauer spectroscopy: trapping reactive intermediates

Krebs, Carsten / Martin Bollinger, J. Jr

Photosynthesis research. 2009 Dec., v. 102, no. 2-3

2009

Abstract: Fe-Mössbauer spectroscopy is a method that probes transitions between the nuclear ground state (I = 1/2) and the first nuclear excited state (I = 3/2). This technique provides detailed information about the chemical environment and electronic structure ...

Abstract	⁵⁷Fe-Mössbauer spectroscopy is a method that probes transitions between the nuclear ground state (I = 1/2) and the first nuclear excited state (I = 3/2). This technique provides detailed information about the chemical environment and electronic structure of iron. Therefore, it has played an important role in studies of the numerous iron-containing proteins and enzymes. In conjunction with the freeze-quench method, ⁵⁷Fe-Mössbauer spectroscopy allows for monitoring changes of the iron site(s) during a biochemical reaction. This approach is particularly powerful for detection and characterization of reactive intermediates. Comparison of experimentally determined Mössbauer parameters to those predicted by density functional theory for hypothetical model structures can then provide detailed insight into the structures of reactive intermediates. We have recently used this methodology to study the reactions of various mononuclear non-heme-iron enzymes by trapping and characterizing several Fe(IV)-oxo reaction intermediates. In this article, we summarize these findings and demonstrate the potential of the method.
Keywords	enzymes ; iron ; proteins ; spectroscopy
Language	English
Dates of publication	2009-12
Size	p. 295-304.
Publisher	Springer Netherlands
Publishing place	Dordrecht
Document type	Article
ZDB-ID	1475688-2
ISSN	1573-5079 ; 0166-8595
ISSN (online)	1573-5079
ISSN	0166-8595
DOI	10.1007/s11120-009-9406-6
Database	NAL-Catalogue (AGRICOLA)

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Article: Cyanobacterial alkane biosynthesis further expands the catalytic repertoire of the ferritin-like ‘di-iron-carboxylate’ proteins

Krebs, Carsten / Bollinger, J Martin, Jr / Booker, Squire J

Current Opinion in Chemical Biology. 2011 Apr., v. 15, no. 2

2011

Abstract: Enzymes that activate dioxygen at carboxylate-bridged non-heme diiron clusters residing within ferritin-like, four-helix-bundle protein architectures have crucial roles in, among other processes, the global carbon cycle (e.g. soluble methane ... ...

Abstract	Enzymes that activate dioxygen at carboxylate-bridged non-heme diiron clusters residing within ferritin-like, four-helix-bundle protein architectures have crucial roles in, among other processes, the global carbon cycle (e.g. soluble methane monooxygenase), fatty acid biosynthesis [plant fatty acyl–acyl carrier protein (ACP) desaturases], DNA biosynthesis [the R2 or β2 subunits of class Ia ribonucleotide reductases (RNRs)], and cellular iron trafficking (ferritins). Classic studies on class Ia RNRs showed long ago how this obligatorily oxidative di-iron/O2 chemistry can be used to activate an enzyme for even a reduction reaction, and more recent investigations of class Ib and Ic RNRs, coupled with earlier studies on dimanganese catalases, have shown that members of this protein family can also incorporate either one or two Mn ions and use them in place of iron for redox catalysis. These two strategies – oxidative activation for non-oxidative reactions and use of alternative metal ions – expand the catalytic repertoire of the family, probably to include activities that remain to be discovered. Indeed, a recent study has suggested that fatty aldehyde decarbonylases (ADs) from cyanobacteria, purported to catalyze a redox-neutral cleavage of a Cn aldehyde to the Cn−1 alkane (or alkene) and CO, also belong to this enzyme family and are most similar in structure to two other members with heterodinuclear (Mn–Fe) cofactors. Here, we first briefly review both the chemical principles underlying the O2-dependent oxidative chemistry of the ‘classical’ di-iron-carboxylate proteins and the two aforementioned strategies that have expanded their functional range, and then consider what metal ion(s) and what chemical mechanism(s) might be employed by the newly discovered cyanobacterial ADs.
Keywords	manganese ; fatty acids ; proteins ; biosynthesis ; catalytic activity ; enzymes ; DNA ; iron ; carbon cycle ; alkanes ; Cyanobacteria ; metal ions
Language	English
Dates of publication	2011-04
Size	p. 291-303.
Publishing place	Elsevier Ltd
Document type	Article
Note	2019-12-06
ZDB-ID	1439176-4
ISSN	1879-0402 ; 1367-5931
ISSN (online)	1879-0402
ISSN	1367-5931
DOI	10.1016/j.cbpa.2011.02.019
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Article: Four-electron oxidation of p-hydroxylaminobenzoate to p-nitrobenzoate by a peroxodiferric complex in AurF from Streptomyces thioluteus

Li, Ning / Korboukh, Victoria Korneeva / Krebs, Carsten / Bollinger, J. Martin Jr

Proceedings of the National Academy of Sciences of the United States of America. 2010 Sept. 7, v. 107, no. 36

2010

Abstract: The nonheme di-iron oxygenase, AurF, converts p-aminobenzoate (Ar-NH₂, where Ar = 4-carboxyphenyl) to p-nitrobenzoate (Ar-NO₂) in the biosynthesis of the antibiotic, aureothin, by Streptomyces thioluteus. It has been reported that this net six-electron ... ...

Abstract	The nonheme di-iron oxygenase, AurF, converts p-aminobenzoate (Ar-NH₂, where Ar = 4-carboxyphenyl) to p-nitrobenzoate (Ar-NO₂) in the biosynthesis of the antibiotic, aureothin, by Streptomyces thioluteus. It has been reported that this net six-electron oxidation proceeds in three consecutive, two-electron steps, through p-hydroxylaminobenzoate (Ar-NHOH) and p-nitrosobenzoate (Ar-NO) intermediates, with each step requiring one equivalent of O₂ and two exogenous reducing equivalents. We recently demonstrated that a peroxodiiron(III/III) complex (peroxo-Formula -AurF) formed by addition of O₂ to the diiron(II/II) enzyme (Formula -AurF) effects the initial oxidation of Ar-NH₂, generating a μ-(oxo)diiron(III/III) form of the enzyme (μ-oxo-Formula -AurF) and (presumably) Ar-NHOH. Here we show that peroxo-Formula -AurF also oxidizes Ar-NHOH. Unexpectedly, this reaction proceeds through to the Ar-NO₂ final product, a four-electron oxidation, and produces Formula -AurF, with which O₂ can combine to regenerate peroxo-Formula -AurF. Thus, conversion of Ar-NHOH to Ar-NO₂ requires only a single equivalent of O₂ and (starting from Formula -AurF or peroxo-Formula -AurF) is fully catalytic in the absence of exogenous reducing equivalents, by contrast to the published stoichiometry. This novel type of four-electron N-oxidation is likely also to occur in the reaction sequences of nitro-installing di-iron amine oxygenases in the biosyntheses of other natural products.
Keywords	Streptomyces thioluteus ; antibiotics ; biosynthesis ; nitrobenzoic acids ; oxidation ; oxygen ; oxygenases ; stoichiometry
Language	English
Dates of publication	2010-0907
Size	p. 15722-15727.
Publishing place	National Academy of Sciences
Document type	Article
ZDB-ID	209104-5
ISSN	1091-6490 ; 0027-8424
ISSN (online)	1091-6490
ISSN	0027-8424
DOI	10.1073/pnas.1002785107
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Article ; Online: Molecular basis for enantioselective herbicide degradation imparted by aryloxyalkanoate dioxygenases in transgenic plants.

Chekan, Jonathan R / Ongpipattanakul, Chayanid / Wright, Terry R / Zhang, Bo / Bollinger, J Martin / Rajakovich, Lauren J / Krebs, Carsten / Cicchillo, Robert M / Nair, Satish K

Proceedings of the National Academy of Sciences of the United States of America

2019 Volume 116, Issue 27, Page(s) 13299–13304

Abstract: The synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) is an active ingredient of thousands of commercial herbicides. Multiple species of bacteria degrade 2,4-D via a pathway initiated by the Fe(II) and α-ketoglutarate (Fe/αKG)-dependent ... ...

Abstract	The synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) is an active ingredient of thousands of commercial herbicides. Multiple species of bacteria degrade 2,4-D via a pathway initiated by the Fe(II) and α-ketoglutarate (Fe/αKG)-dependent aryloxyalkanoate dioxygenases (AADs). Recently, genes encoding 2 AADs have been deployed commercially in herbicide-tolerant crops. Some AADs can also inactivate chiral phenoxypropionate and aryloxyphenoxypropionate (AOPP) herbicides, albeit with varying substrate enantioselectivities. Certain AAD enzymes, such as AAD-1, have expanded utility in weed control systems by enabling the use of diverse modes of action with a single trait. Here, we report 1) the use of a genomic context-based approach to identify 59 additional members of the AAD class, 2) the biochemical characterization of AAD-2 from
MeSH term(s)	2,4-Dichlorophenoxyacetic Acid/metabolism ; Dioxygenases/chemistry ; Dioxygenases/metabolism ; Herbicide Resistance ; Herbicides/chemistry ; Herbicides/metabolism ; Indoleacetic Acids/metabolism ; Plant Proteins/chemistry ; Plant Proteins/metabolism ; Plants, Genetically Modified/enzymology ; Plants, Genetically Modified/metabolism ; Protein Structure, Tertiary ; Glycine max ; Stereoisomerism ; Structure-Activity Relationship ; Zea mays
Chemical Substances	Herbicides ; Indoleacetic Acids ; Plant Proteins ; 2,4-Dichlorophenoxyacetic Acid (2577AQ9262) ; Dioxygenases (EC 1.13.11.-)
Language	English
Publishing date	2019-06-17
Publishing country	United States
Document type	Journal Article ; Research Support, N.I.H., Extramural
ZDB-ID	209104-5
ISSN	1091-6490 ; 0027-8424
ISSN (online)	1091-6490
ISSN	0027-8424
DOI	10.1073/pnas.1900711116
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Article: Evidence for the slow reaction of hypoxia-inducible factor prolyl hydroxylase 2 with oxygen

Flashman, Emily / Hoffart, Lee M / Hamed, Refaat B / Bollinger Jr, J. Martin / Krebs, Carsten / Schofield, Christopher J

FEBS journal. 2010 Oct., v. 277, no. 19

2010

Abstract: The response of animals to hypoxia is mediated by the hypoxia-inducible transcription factor. Human hypoxia-inducible factor is regulated by four Fe(II)- and 2-oxoglutarate-dependent oxygenases: prolyl hydroxylase domain enzymes 1-3 catalyse ... ...

Abstract	The response of animals to hypoxia is mediated by the hypoxia-inducible transcription factor. Human hypoxia-inducible factor is regulated by four Fe(II)- and 2-oxoglutarate-dependent oxygenases: prolyl hydroxylase domain enzymes 1-3 catalyse hydroxylation of two prolyl-residues in hypoxia-inducible factor, triggering its degradation by the proteasome. Factor inhibiting hypoxia-inducible factor catalyses the hydroxylation of an asparagine-residue in hypoxia-inducible factor, inhibiting its transcriptional activity. Collectively, the hypoxia-inducible factor hydroxylases negatively regulate hypoxia-inducible factor in response to increasing oxygen concentration. Prolyl hydroxylase domain 2 is the most important oxygen sensor in human cells; however, the underlying kinetic basis of the oxygen-sensing function of prolyl hydroxylase domain 2 is unclear. We report analyses of the reaction of prolyl hydroxylase domain 2 with oxygen. Chemical quench/MS experiments demonstrate that reaction of a complex of prolyl hydroxylase domain 2, Fe(II), 2-oxoglutarate and the C-terminal oxygen-dependent degradation domain of hypoxia-inducible factor-α with oxygen to form hydroxylated C-terminal oxygen-dependent degradation domain and succinate is much slower (approximately 100-fold) than for other similarly studied 2-oxoglutarate oxygenases. Stopped flow/UV-visible spectroscopy experiments demonstrate that the reaction produces a relatively stable species absorbing at 320 nm; Mössbauer spectroscopic experiments indicate that this species is likely not a Fe(IV)=O intermediate, as observed for other 2-oxoglutarate oxygenases. Overall, the results obtained suggest that, at least compared to other studied 2-oxoglutarate oxygenases, prolyl hydroxylase domain 2 reacts relatively slowly with oxygen, a property that may be associated with its function as an oxygen sensor.
Keywords	oxygen ; procollagen-proline dioxygenase ; spectroscopy
Language	English
Dates of publication	2010-10
Size	p. 4089-4099.
Publisher	Blackwell Publishing Ltd
Publishing place	Oxford, UK
Document type	Article
ZDB-ID	2173655-8
ISSN	1742-4658 ; 1742-464X
ISSN (online)	1742-4658
ISSN	1742-464X
DOI	10.1111/j.1742-4658.2010.07804.x
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Article: Substrate positioning controls the partition between halogenation and hydroxylation in the aliphatic halogenase, SyrB2

Matthews, Megan L / Neumann, Christopher S / Miles, Linde A / Grove, Tyler L / Booker, Squire J / Krebs, Carsten / Walsh, Christopher T / Bollinger, J. Martin Jr

Proceedings of the National Academy of Sciences of the United States of America. 2009 Oct. 20, v. 106, no. 42

2009

Abstract: The Î±-ketoglutarate-dependent hydroxylases and halogenases employ similar reaction mechanisms involving hydrogen-abstracting Fe(IV)-oxo (ferryl) intermediates. In the halogenases, the carboxylate residue from the Hisâ(Asp/Glu)â"facial triad" of iron ...

Abstract	The Î±-ketoglutarate-dependent hydroxylases and halogenases employ similar reaction mechanisms involving hydrogen-abstracting Fe(IV)-oxo (ferryl) intermediates. In the halogenases, the carboxylate residue from the Hisâ(Asp/Glu)â"facial triad" of iron ligands found in the hydroxylases is replaced by alanine, and a halide ion (Xâ») coordinates at the vacated site. Halogenation is thought to result from "rebound" of the halogen radical from the X-Fe(III)-OH intermediate produced by hydrogen (H{bullet}) abstraction to the substrate radical. The alternative decay pathway for the X-Fe(III)-OH intermediate, rebound of the hydroxyl radical to the substrate radical (as occurs in the hydroxylases), reportedly does not compete. Here we show for the halogenase SyrB2 that positioning of the alkyl group of the substrate away from the oxo/hydroxo ligand and closer to the halogen ligand sacrifices H{bullet}-abstraction proficiency for halogen-rebound selectivity. Upon replacement of L-Thr, the C4 amino acid tethered to the SyrB1 carrier protein in the native substrate, by the C5 amino acid L-norvaline, decay of the chloroferryl intermediate becomes 130x faster and the reaction outcome switches to primarily hydroxylation of C5, consistent with projection of the methyl group closer to the oxo/hydroxo by the longer side chain. Competing H{bullet} abstraction from C4 results primarily in chlorination, as occurs at this site in the native substrate. Consequently, deuteration of C5, which slows attack at this site, switches both the regioselectivity from C5 to C4 and the chemoselectivity from hydroxylation to chlorination. Thus, substrate-intermediate disposition and the carboxylate [rightward arrow] halide ligand swap combine to specify the halogenation outcome.
Keywords	alanine ; chlorination ; hydrogen ; hydroxyl radicals ; hydroxylation ; iron ; ligands ; reaction mechanisms
Language	English
Dates of publication	2009-1020
Size	p. 17723-17728.
Publishing place	National Academy of Sciences
Document type	Article
ZDB-ID	209104-5
ISSN	1091-6490 ; 0027-8424
ISSN (online)	1091-6490
ISSN	0027-8424
DOI	10.1073/pnas.0909649106
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Article: A Manganese(IV)/Iron(III) Cofactor in Chlamydia trachomatis Ribonucleotide Reductase

Jiang, Wei / Barr, Eric W / Bollinger, J. Martin Jr / Hoffart, Lee M / Krebs, Carsten / Maslak, Monique-Anne / Saleh, Lana / Xing, Gang / Yun, Danny

Science. 2007 May 25, v. 316, no. 5828

2007

Abstract: In a conventional class I ribonucleotide reductase (RNR), a diiron(II/II) cofactor in the R2 subunit reacts with oxygen to produce a diiron(III/IV) intermediate, which generates a stable tyrosyl radical (Y{bullet}). The Y{bullet} reversibly oxidizes a ... ...

Abstract	In a conventional class I ribonucleotide reductase (RNR), a diiron(II/II) cofactor in the R2 subunit reacts with oxygen to produce a diiron(III/IV) intermediate, which generates a stable tyrosyl radical (Y{bullet}). The Y{bullet} reversibly oxidizes a cysteine residue in the R1 subunit to a cysteinyl radical (C{bullet}), which abstracts the 3'-hydrogen of the substrate to initiate its reduction. The RNR from Chlamydia trachomatis lacks the Y{bullet}, and it had been proposed that the diiron(III/IV) complex in R2 directly generates the C{bullet} in R1. By enzyme activity measurements and spectroscopic methods, we show that this RNR actually uses a previously unknown stable manganese(IV)/iron(III) cofactor for radical initiation.
Keywords	Chlamydia trachomatis ; cysteine ; enzyme activity ; manganese ; oxygen ; ribonucleotide reductase ; spectroscopy
Language	English
Dates of publication	2007-0525
Size	p. 1188-1191.
Publishing place	American Association for the Advancement of Science
Document type	Article
ZDB-ID	128410-1
ISSN	1095-9203 ; 0036-8075
ISSN (online)	1095-9203
ISSN	0036-8075
DOI	10.1126/science.1141179
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Article: Electronic Structure of the Ferryl Intermediate in the Î±-Ketoglutarate Dependent Non-Heme Iron Halogenase SyrB2: Contributions to H Atom Abstraction Reactivity

Srnec, Martin / Bollinger J. Martin / Krebs Carsten / Matthews Megan L / Solomon Edward I / Wong Shaun D

Journal of the American Chemical Society. 2016 Apr. 20, v. 138, no. 15

2016

Abstract: ... model complex (TMGâtren)Feá´µâ±½î»O (Srnec, M.; Wong, S. D.; England, J.; Que, L. Jr.; Solomon, E ...

Abstract	Low temperature magnetic circular dichroism (LT MCD) spectroscopy in combination with quantum-chemical calculations are used to define the electronic structure associated with the geometric structure of the Feá´µâ±½î»O intermediate in SyrB2 that was previously determined by nuclear resonance vibrational spectroscopy. These studies elucidate key frontier molecular orbitals (FMOs) and their contribution to H atom abstraction reactivity. The VT MCD spectra of the enzymatic S = 2 Feá´µâ±½î»O intermediate with Brâ ligation contain information-rich features that largely parallel the corresponding spectra of the S = 2 model complex (TMGâtren)Feá´µâ±½î»O (Srnec, M.; Wong, S. D.; England, J.; Que, L. Jr.; Solomon, E. I. Proc. Natl. Acad. Sci. USA 2012, 109, 14326â14331). However, quantitative differences are observed that correlate with Ï-anisotropy and oxo donor strength that perturb FMOs and affect reactivity. Due to Ï-anisotropy, the Feá´µâ±½î»O active site exhibits enhanced reactivity in the direction of the substrate cavity that proceeds through a Ï-channel that is controlled by perpendicular orientation of the substrate CâH bond relative to the halideâFeá´µâ±½î»O plane. Also, the increased intrinsic reactivity of the SyrB2 intermediate relative to the ferryl model complex is correlated to a higher oxyl character of the Feá´µâ±½î»O at the transition states resulting from the weaker ligand field of the halogenase.
Keywords	active sites ; alpha-ketoglutaric acid ; bromides ; chemical bonding ; chemical elements ; circular dichroism spectroscopy ; geometry ; ligands ; models ; quantum mechanics
Language	English
Dates of publication	2016-0420
Size	p. 5110-5122.
Publishing place	American Chemical Society
Document type	Article
ZDB-ID	3155-0
ISSN	1520-5126 ; 0002-7863
ISSN (online)	1520-5126
ISSN	0002-7863
DOI	10.1021/jacs.6b01151
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Article: AurF from Streptomyces thioluteus and a possible new family of manganese/iron oxygenases.

Krebs, Carsten / Matthews, Megan L / Jiang, Wei / Bollinger, J Martin

Biochemistry

2007 Volume 46, Issue 37, Page(s) 10413–10418

Abstract: ... G., Hoffart, L. M., Maslak, M.-A., Krebs, C., and Bollinger, J. M., Jr. (2007) Science 316, 1188 ...

Abstract	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 AurF presented in one of these studies is markedly similar to the spectrum of the MnIII/FeIII 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 O2 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.
MeSH term(s)	Amino Acid Sequence ; Bacterial Proteins/chemistry ; Catalysis ; Chlamydia trachomatis/enzymology ; Chromones/chemistry ; Electron Spin Resonance Spectroscopy ; Iron/chemistry ; Manganese/chemistry ; Molecular Sequence Data ; Oxygenases/chemistry ; Sequence Alignment ; Streptomyces/enzymology
Chemical Substances	Bacterial Proteins ; Chromones ; Manganese (42Z2K6ZL8P) ; Iron (E1UOL152H7) ; Oxygenases (EC 1.13.-) ; aureothin (G359FGQ2RB)
Language	English
Publishing date	2007-09-18
Publishing country	United States
Document type	Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
ZDB-ID	1108-3
ISSN	1520-4995 ; 0006-2960
ISSN (online)	1520-4995
ISSN	0006-2960
DOI	10.1021/bi701060g
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Article: A manganese(IV)/iron(IV) intermediate in assembly of the manganese(IV)/iron(III) cofactor of Chlamydia trachomatis ribonucleotide reductase.

Jiang, Wei / Hoffart, Lee M / Krebs, Carsten / Bollinger, J Martin

Biochemistry

2007 Volume 46, Issue 30, Page(s) 8709–8716

Abstract: ... and Bollinger, J. M., Jr. (2007) Science 316, 1188-1191]. Here, we have dissected the mechanism ...

Abstract	We recently showed that the class Ic ribonucleotide reductase from the human pathogen Chlamydia trachomatis uses a Mn(IV)/Fe(III) cofactor to generate protein and substrate radicals in its catalytic mechanism [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]. Here, we have dissected the mechanism of formation of this novel heterobinuclear redox cofactor from the Mn(II)/Fe(II) cluster and O2. An intermediate with a g = 2 EPR signal that shows hyperfine coupling to both 55Mn and 57Fe accumulates almost quantitatively in a second-order reaction between O2 and the reduced R2 complex. The otherwise slow decay of the intermediate to the active Mn(IV)/Fe(III)-R2 complex is accelerated by the presence of the one-electron reductant, ascorbate, implying that the intermediate is more oxidized than Mn(IV)/Fe(III). Mössbauer spectra show that the intermediate contains a high-spin Fe(IV) center. Its chemical and spectroscopic properties establish that the intermediate is a Mn(IV)/Fe(IV)-R2 complex with an S = 1/2 electronic ground state arising from antiferromagnetic coupling between the Mn(IV) (S(Mn) = 3/2) and high-spin Fe(IV) (S(Fe) = 2) sites.
MeSH term(s)	Antigens, Bacterial ; Chlamydia trachomatis/chemistry ; Chlamydia trachomatis/enzymology ; Electron Spin Resonance Spectroscopy ; Electron Transport ; Ferrous Compounds/chemistry ; Ferrous Compounds/metabolism ; Free Radicals/chemistry ; Free Radicals/metabolism ; Humans ; Iron/chemistry ; Iron/metabolism ; Manganese/chemistry ; Manganese/metabolism ; Oxidation-Reduction ; Oxygen/chemistry ; Oxygen/metabolism ; Ribonucleotide Reductases/chemistry ; Ribonucleotide Reductases/metabolism ; Spectroscopy, Mossbauer
Chemical Substances	Antigens, Bacterial ; Ferrous Compounds ; Free Radicals ; Manganese (42Z2K6ZL8P) ; Iron (E1UOL152H7) ; Ribonucleotide Reductases (EC 1.17.4.-) ; ribonucleotide reductase R2 subunit (EC 1.17.4.-) ; Oxygen (S88TT14065)
Language	English
Publishing date	2007-07-31
Publishing country	United States
Document type	Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
ZDB-ID	1108-3
ISSN	1520-4995 ; 0006-2960
ISSN (online)	1520-4995
ISSN	0006-2960
DOI	10.1021/bi700906g
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In stock of ZB MED Bonn / Germany

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Inter-library loan at ZB MED

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In stock of ZB MED Bonn / Germany

Order via subito

Inter-library loan at ZB MED

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In stock of ZB MED Cologne/Königswinter

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In stock of ZB MED Cologne/Königswinter

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