Structural basis for the network of functional cooperativities in cytochrome c3 from Desulfovibrio gigas: solution structures of the oxidised and reduced states

Brennan, Lorraine; Turner, David L.; Messias, Ana C.; Teodoro, Miguel L.; LeGall, Jean; Santos, Helena; Xavier, António V.

doi:10.1006/jmbi.2000.3652

Cited by 66 publications

(70 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2. The experimental and calculated paramagnetic 13 C shifts of the a-substituents to the porphyrin ring are also depicted in this figure, showing that the pattern of shifts obtained by fitting the model to the data is well described by the model of the heme molecular orbitals.…”

Section: Axial Ligands Geometrymentioning

confidence: 71%

“…The model for analysing the 13 C shifts of heme signals in terms of the heme molecular orbitals is only valid for low-spin hemes [21]. All heme methyl signals, including those at lowest field, display a linear dependence of the chemical shift with temperature, which indicates that there are no significant contributions from high-spin states in the temperature range 289-307 K (Fig.…”

Section: Axial Ligands Geometrymentioning

confidence: 99%

“…1 Supplementary data) and thus that the model can be applied. Table 2 Comparison between the molecular orbital parameters obtained by fitting the 13 C signals of the a-substituents of the heme and the geometry of the axial ligands reported in the X-ray structure [8]. The parameter b was calculated from the energy splitting of the molecular orbitals [17].…”

Section: Axial Ligands Geometrymentioning

confidence: 99%

“…Values measured from the crystal structure are different due to the influence of deoxycholate present in the crystal and are included for comparison. The orientation of the heme axial histidine planes was deduced from the pattern of 13 C NMR paramagnetic shifts of the a-substituents of the hemes at the three temperatures (Table 2). These orientations are compared with the data from X-ray structure in Fig.…”

Section: Axial Ligands Geometrymentioning

confidence: 99%

See 3 more Smart Citations

Orientation of the axial ligands and magnetic properties of the hemes in the triheme ferricytochrome PpcA from G. sulfurreducens determined by paramagnetic NMR

Morgado¹,

Saraiva²,

Louro³

et al. 2010

FEBS Letters

View full text Add to dashboard Cite

a b s t r a c tThe geometry of the axial ligands of the hemes in the triheme cytochrome PpcA from Geobacter sulfurreducens was determined in solution for the ferric form using the unambiguous assignment of the NMR signals of the a-substituents of the hemes. The paramagnetic 13 C shifts of the hemes can be used to define the heme electronic structure, the geometry of the axial ligands, and the magnetic susceptibility tensor. The latter establishes the magnitude and geometrical dependence of the pseudocontact shifts, which are crucial to warrant reliable structural constraints for a detailed structural characterization of this paramagnetic protein in solution.

show abstract

Section: Axial Ligands Geometrymentioning

confidence: 71%

Section: Axial Ligands Geometrymentioning

confidence: 99%

Section: Axial Ligands Geometrymentioning

confidence: 99%

Section: Axial Ligands Geometrymentioning

confidence: 99%

See 2 more Smart Citations

Orientation of the axial ligands and magnetic properties of the hemes in the triheme ferricytochrome PpcA from G. sulfurreducens determined by paramagnetic NMR

Morgado¹,

Saraiva²,

Louro³

et al. 2010

FEBS Letters

View full text Add to dashboard Cite

show abstract

“…This reorientation results in the breakage of three hydrogen bonds established by T24 in the oxidized state: between H N and O γ1 of T24, between T24 H γ1 and one of the carboxyl oxygen atoms of heme III propionate 17, and between T24 O γ1 and H δ1 of the heme III axial ligand, H25 (28) ( Figure 1). In DesulfoVibrio gigas cytochrome c 3 the homologous residue T28 undergoes a similar redox-linked reorientation in solution (32). To investigate the effect of this redox-linked conformational change on the general redox properties of DVHc 3 , T24 was replaced by the nonpolar residue valine, and the thermodynamic properties of the mutated cytochrome were analyzed.…”

mentioning

confidence: 99%

Effect of Hydrogen-Bond Networks in Controlling Reduction Potentials in Desulfovibrio vulgaris (Hildenborough) Cytochrome c₃ Probed by Site-Specific Mutagenesis

et al. 2001

Self Cite

View full text Add to dashboard Cite

Cytochromes c 3 isolated from DesulfoVibrio spp. are periplasmic proteins that play a central role in energy transduction by coupling the transfer of electrons and protons from hydrogenase. Comparison between the oxidized and reduced structures of cytochrome c 3 isolated from DesulfoVibrio Vulgaris (Hildenborough) show that the residue threonine 24, located in the vicinity of heme III, reorients between these two states [Messias, A. C., Kastrau, D. H. W., Costa, H. S., LeGall, J., Turner, D. L., Santos, H., and Xavier, A. V. (1998) J. Mol. Biol. 281,. Threonine 24 was replaced with valine by sitedirected mutagenesis to elucidate its effect on the redox properties of the protein. The NMR spectra of the mutated protein are very similar to those of the wild type, showing that the general folding and heme core architecture are not affected by the mutation. However, thermodynamic analysis of the mutated cytochrome reveals a large alteration in the microscopic reduction potential of heme III (75 and 106 mV for the protonated forms of the fully reduced and oxidized states, respectively). The redox interactions involving this heme are also modified, while the remaining heme-heme interactions and the redoxBohr interactions are less strongly affected. Hence, the order of oxidation of the hemes in the mutated cytochrome is different from that in the wild type, and it has a higher overall affinity for electrons. This is consistent with the replacement of threonine 24 by valine preventing the formation of a network of hydrogen bonds, which stabilizes the oxidized state. The mutated protein is unable to perform a concerted two-electron step between the intermediate oxidation stages, 1 and 3, which can occur in the wild-type protein. Thus, replacing a single residue unbalances the global network of cooperativities tuned to control thermodynamically the directionality of the stepwise electron transfer and may affect the functionality of the protein.

show abstract

Tetraheme CytochromesC₃

Bento¹,

Louro²,

Soares³

et al. 2004

Handbook of Metalloproteins

View full text Add to dashboard Cite

Tetraheme cytochromes c 3 constitute the best‐studied group among the multiheme cytochromes belonging to the class III of Ambler's classification. Since 1954, when cytochrome c 3 was isolated from Desulfovibrio vulgaris for the first time by Postgate, these proteins have been widely characterized, especially those from the Desulfovibrio ( D .) genus. All these cytochromes have their heme group attached to the polypeptide chain by cysteine residues and show bis‐histidinyl coordination of the heme iron and a highly conserved heme‐binding motif (CXXCH or CXXXXCH). Cytochromes c 3 show a wide variety of redox potentials, ranging from 0 to −400 mV, are usually periplasmatic proteins, and are believed to play key roles in the electron transfer chains. Recently, the cytochrome c 3 group was divided into two main types on the basis of structural, functional, and genetic differences: type I cytochrome c 3 (TpI‐ c 3 ) and type II cytochrome c 3 (TpII‐ c 3 ). This paper reviews their structural, spectroscopic, and functional properties, based on the wealth of information currently available. These include physicochemical properties, redox mechanisms, coupling between electron and proton transfer, and data concerning the interaction with their redox partners obtained by experimental and molecular modeling methods.

show abstract

Structural basis for the network of functional cooperativities in cytochrome c3 from Desulfovibrio gigas: solution structures of the oxidised and reduced states

Cited by 66 publications

References 92 publications

Orientation of the axial ligands and magnetic properties of the hemes in the triheme ferricytochrome PpcA from G. sulfurreducens determined by paramagnetic NMR

Orientation of the axial ligands and magnetic properties of the hemes in the triheme ferricytochrome PpcA from G. sulfurreducens determined by paramagnetic NMR

Effect of Hydrogen-Bond Networks in Controlling Reduction Potentials in Desulfovibrio vulgaris (Hildenborough) Cytochrome c₃ Probed by Site-Specific Mutagenesis

Tetraheme CytochromesC₃

Contact Info

Product

Resources

About

Structural basis for the network of functional cooperativities in cytochrome c3 from Desulfovibrio gigas: solution structures of the oxidised and reduced states

Cited by 66 publications

References 92 publications

Orientation of the axial ligands and magnetic properties of the hemes in the triheme ferricytochrome PpcA from G. sulfurreducens determined by paramagnetic NMR

Orientation of the axial ligands and magnetic properties of the hemes in the triheme ferricytochrome PpcA from G. sulfurreducens determined by paramagnetic NMR

Effect of Hydrogen-Bond Networks in Controlling Reduction Potentials in Desulfovibrio vulgaris (Hildenborough) Cytochrome c3 Probed by Site-Specific Mutagenesis

Tetraheme CytochromesC3

Contact Info

Product

Resources

About

Effect of Hydrogen-Bond Networks in Controlling Reduction Potentials in Desulfovibrio vulgaris (Hildenborough) Cytochrome c₃ Probed by Site-Specific Mutagenesis

Tetraheme CytochromesC₃