Related ArticlesProton NMR of Escherichia coli sulfite reductase: studies of the heme protein subunit with added ligands.
Biochemistry. 1993 Aug 31;32(34):8782-91
Authors: Kaufman J, Siegel LM, Spicer LD
The heme protein subunit of sulfite reductase (SiR-HP; M(r) 64,000) from Escherichia coli as isolated contains the isobacteriochlorin siroheme exchange-coupled to a [4Fe-4S] cluster in the 2+ oxidation state. SiR-HP in the presence of a suitable electron donor can catalyze the six-electron reductions of sulfite to sulfide and nitrite to ammonia. Paramagnetic 1H NMR was used to study the low-spin complexes of SiR-HP formed by binding the exogenous inhibitor cyanide or the substrates sulfite and nitrite. As a model, the cyanide complex of purified siroheme was also prepared. The NMR spectrum of isolated ferric low-spin siroheme-CN is consistent with spin density being transferred into the a2u molecular orbital, an interaction which is symmetry-forbidden in porphyrins. The pattern of proton NMR shifts observed for isolated ferric low-spin siroheme-CN is very similar to those obtained for the protein-cyanide complex. NMR spectra of the cyanide complex of SiR-HP were obtained in all three accessible redox states. The pattern of hyperfine shifts observed for the one-electron and two-electron reduced cyanide complexes is typical of those seen for [4Fe-4S] clusters in the 2+ and 1+ oxidation states, respectively. Resonances arising from the beta-CH2 protons of cluster cysteines have been assigned for all complexes studied utilizing deuterium substitution. The cyanide-, sulfite-, and nitrite-ligated states possessed an almost identically shifted upfield cluster cysteine resonance whose presence indicates that covalent coupling exists between siroheme and cluster in solution. Data are also presented for the existence of a secondary anion binding site, the occupancy of which perturbs the oxidized SiR-HP NMR spectrum, where binding occurs at a rate much faster than that of ligand binding to heme.
[NMR paper] Elucidation of the epsilon-theta subunit interface of Escherichia coli DNA polymerase
Elucidation of the epsilon-theta subunit interface of Escherichia coli DNA polymerase III by NMR spectroscopy.
Related Articles Elucidation of the epsilon-theta subunit interface of Escherichia coli DNA polymerase III by NMR spectroscopy.
Biochemistry. 2003 Apr 8;42(13):3635-44
Authors: DeRose EF, Darden T, Harvey S, Gabel S, Perrino FW, Schaaper RM, London RE
The DNA polymerase III holoenzyme (HE) is the primary replicative polymerase of Escherichia coli. The epsilon (epsilon) subunit of HE provides the 3'-->5' exonucleolytic proofreading...
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[NMR paper] Refolding of [6-19F]tryptophan-labeled Escherichia coli dihydrofolate reductase in th
Refolding of tryptophan-labeled Escherichia coli dihydrofolate reductase in the presence of ligand: a stopped-flow NMR spectroscopy study.
Related Articles Refolding of tryptophan-labeled Escherichia coli dihydrofolate reductase in the presence of ligand: a stopped-flow NMR spectroscopy study.
Biochemistry. 1998 Jan 6;37(1):387-98
Authors: Hoeltzli SD, Frieden C
Escherichia coli dihydrofolate reductase contains five tryptophan residues that are spatially distributed throughout the protein and located in different secondary structural elements....
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[NMR paper] Studies on the NusB protein of Escherichia coli--expression and determination of seco
Studies on the NusB protein of Escherichia coli--expression and determination of secondary-structure elements by multinuclear NMR spectroscopy.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif Related Articles Studies on the NusB protein of Escherichia coli--expression and determination of secondary-structure elements by multinuclear NMR spectroscopy.
Eur J Biochem. 1997 Sep 1;248(2):338-46
Authors: Berglechner F, Richter G, Fischer M, Bacher A, Gschwind RM,...
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[NMR paper] Structural features of the epsilon subunit of the Escherichia coli ATP synthase deter
Structural features of the epsilon subunit of the Escherichia coli ATP synthase determined by NMR spectroscopy.
Related Articles Structural features of the epsilon subunit of the Escherichia coli ATP synthase determined by NMR spectroscopy.
Nat Struct Biol. 1995 Nov;2(11):961-7
Authors: Wilkens S, Dahlquist FW, McIntosh LP, Donaldson LW, Capaldi RA
The tertiary fold of the epsilon subunit of the Escherichia coli F1F0 ATPsynthase (ECF1F0) has been determined by two- and three-dimensional heteronuclear (13C, 15N) NMR spectroscopy. The epsilon...
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[NMR paper] Proton NMR study on a histone-like protein, HU alpha, from Escherichia coli and its c
Proton NMR study on a histone-like protein, HU alpha, from Escherichia coli and its complex with oligo DNAs.
Related Articles Proton NMR study on a histone-like protein, HU alpha, from Escherichia coli and its complex with oligo DNAs.
Biol Pharm Bull. 1993 May;16(5):437-43
Authors: Shindo H, Kurumizaka H, Furubayashi A, Sakuma C, Matsumoto U, Yanagida A, Goshima N, Kano Y, Imamoto F
It was confirmed that the flexible arm region of HU alpha forms an antiparallel beta-sheet and that all of the residues of phenylalanines, together with some of...
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[NMR paper] Proton NMR of Escherichia coli sulfite reductase: the unligated hemeprotein subunit.
Proton NMR of Escherichia coli sulfite reductase: the unligated hemeprotein subunit.
Related Articles Proton NMR of Escherichia coli sulfite reductase: the unligated hemeprotein subunit.
Biochemistry. 1993 Mar 23;32(11):2853-67
Authors: Kaufman J, Spicer LD, Siegel LM
The isolated hemeprotein subunit of sulfite reductase (SiR-HP) from Escherichia coli consists of a high spin ferric isobacteriochlorin (siroheme) coupled to a diamagnetic 2+ cluster. When supplied with an artificial electron donor, such as methyl viologen cation radical, SiR-HP...
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[NMR paper] 13C NMR studies of complexes of Escherichia coli dihydrofolate reductase formed with
13C NMR studies of complexes of Escherichia coli dihydrofolate reductase formed with methotrexate and with folic acid.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-PubMedLink.gif Related Articles 13C NMR studies of complexes of Escherichia coli dihydrofolate reductase formed with methotrexate and with folic acid.
FEBS Lett. 1992 Nov 9;312(2-3):147-51
Authors: Cheung HT, Birdsall B, Feeney J
13C NMR studies of 13C-labelled ligands bound to dihydrofolate reductase provide (DHFR) a powerful means of...
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[NMR paper] Studies on ribonucleoside-diphosphate reductase from Escherichia coli. The product dC
Studies on ribonucleoside-diphosphate reductase from Escherichia coli. The product dCDP is a competitive inhibitor and functions as a spectroscopic probe for the substrate binding site; demonstration by enzyme kinetics and 1H NMR.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif Related Articles Studies on ribonucleoside-diphosphate reductase from Escherichia coli. The product dCDP is a competitive inhibitor and functions as a spectroscopic probe for the substrate binding site;...