Insights into Signal Transduction Involving PAS Domain Oxygen-Sensing Heme Proteins from the X-ray Crystal Structure of <i>Escherichia Coli</i> Dos Heme Domain (<i>Ec</i> DosH)

Park, HaJeung; Suquet, Christine; Satterlee, James D.; Kang, ChulHee

doi:10.1021/bi035980p

Cited by 119 publications

(238 citation statements)

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“…The three-dimensional structures of the Fe(III), Fe(II), and Fe(II)-O 2 complexes of the isolated heme sensor domain of EcDosH (EcDosH) have been determined (7,8). These structures have revealed the importance of several key amino acids near the distal heme-binding site involved in changes in the heme environment upon O 2 binding.…”

Section: Dos From Escherichia Coli (Ecdos)mentioning

confidence: 99%

“…The heme sensor domain EcDosH crystallizes as a dimer (7,8) and is also dimeric in solution (1). Surprisingly, based on gel filtration chromatography, full-length EcDos has been characterized as a tetramer (12,13).…”

Section: Dos From Escherichia Coli (Ecdos)mentioning

confidence: 99%

“…Cyanide Binding Kinetics-To further investigate the nature of the distal ligand in the ferric state in EcDos proteins in solution (a water molecule in the EcDosH crystal structures (7,8)), we compared the cyanide binding kinetics of EcDos, EcDosH, the M95I mutant, and myoglobin. The binding kinetics of cyanide were pseudo-first order.…”

Section: Size Exclusion Chromatography and Light Scattering-mentioning

confidence: 99%

“…Furthermore, whereas in the ferrous deoxy form of FixL the heme is pentacoordinate, in EcDos the heme iron is coordinated to a proximal histidine (His-77) and a distal methionine (Met-95). Met-95 can be replaced by small gaseous molecules and plays a crucial role in the regulation of the catalytic activity.The three-dimensional structures of the Fe(III), Fe(II), and Fe(II)-O 2 complexes of the isolated heme sensor domain of EcDosH (EcDosH) have been determined (7,8). These structures have revealed the importance of several key amino acids near the distal heme-binding site involved in changes in the heme environment upon O 2 binding.…”

mentioning

confidence: 99%

“…The crucial roles of these residues in regulating the catalytic domain have been studied (9 -11). In the ferric form of crystallized EcDosH, a water molecule rather than Met-95 is bound in the distal heme site (7).The heme sensor domain EcDosH crystallizes as a dimer (7,8) and is also dimeric in solution (1). Surprisingly, based on gel filtration chromatography, full-length EcDos has been characterized as a tetramer (12,13).…”

mentioning

confidence: 99%

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Heme Ligand Binding Properties and Intradimer Interactions in the Full-length Sensor Protein Dos from Escherichia coli and Its Isolated Heme Domain

Lechauve

Bouzhir-Sima

Yamashita

et al. 2009

Journal of Biological Chemistry

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Dos from Escherichia coli is a bacterial gas sensor protein comprising a heme-containing gas sensor domain and a phosphodiesterase catalytic domain. Using a combination of static light scattering and gel filtration experiments, we established that, as are many other sensor proteins, the full-length protein is dimeric. The full-length dimer (association constant <10 nM) is more stable than the dimeric heme domain (association constant ϳ1 M), and the dimer interface presumably includes both sensor and catalytic domains. Ultrafast spectroscopic studies showed little influence of the catalytic domain on kinetic processes in the direct vicinity of the heme. By contrast, the properties of ligand (CO and O 2 ) binding to the heme in the sensor domain, occurring on a microsecond to second time scale, were found to be influenced by (i) the presence of the catalytic domain, (ii) the dimerization state, and in dimers, (iii) the ligation state of the other subunit. These results imply allosteric interactions within dimers. Steady-state titrations demonstrated marked cooperativity in oxygen binding to both the full-length protein and the isolated heme domain, a feature not reported to date for any dimeric sensor protein. Analysis of a variety of time-resolved experiments showed that Met-95 plays a major role in the intradimer interactions. The intrinsic binding and dissociation rates of Met-95 to the heme were modulated ϳ10-fold by intradimer and sensor-catalytic domain interactions. Dimerization effects were also observed for cyanide binding to the ferric heme domains, suggesting a similar role for Met-95 in ferric proteins. Dos from Escherichia coli (EcDos)4 is a modular gas sensor protein in which phosphodiesterase activity is coupled with the binding and release of external ligands in an associated hemebinding sensor domain (1-3). Cyclic AMP (4) and cyclic diGMP act as substrates of this enzyme, the latter with much higher activity (5). EcDos has been found to display 6 -7-fold enhanced catalytic activity toward cyclic diGMP after binding of gaseous molecules such as O 2 , CO, and NO to the heme.Although the heme-containing PAS sensor domains of EcDos and the rhizobial sensor protein FixL (6) share a conserved structural fold, the ligand-induced regulation of both proteins differs considerably. In contrast to EcDos, FixL is an oxygen-specific sensor that couples the status of its sensor domain to the activity of a histidine kinase. This enzymatic activity is decreased to a great extent upon O 2 binding (2). Furthermore, whereas in the ferrous deoxy form of FixL the heme is pentacoordinate, in EcDos the heme iron is coordinated to a proximal histidine (His-77) and a distal methionine (Met-95). Met-95 can be replaced by small gaseous molecules and plays a crucial role in the regulation of the catalytic activity.The three-dimensional structures of the Fe(III), Fe(II), and Fe(II)-O 2 complexes of the isolated heme sensor domain of EcDosH (EcDosH) have been determined (7,8). These structures have revealed the importance of se...

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Section: Dos From Escherichia Coli (Ecdos)mentioning

confidence: 99%

Section: Dos From Escherichia Coli (Ecdos)mentioning

confidence: 99%

Section: Size Exclusion Chromatography and Light Scattering-mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Heme Ligand Binding Properties and Intradimer Interactions in the Full-length Sensor Protein Dos from Escherichia coli and Its Isolated Heme Domain

Lechauve

Bouzhir-Sima

Yamashita

et al. 2009

Journal of Biological Chemistry

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Iron Porphyrin Chemistry

Walker¹,

Simonis²

2005

Encyclopedia of Inorganic Chemistry

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This article reviews most aspects of the chemistry of iron porphyrins, from Fe(0) to Fe(V), including occurrence and roles of natural iron porphyrins (hemes) and their synthetic analogs, structures and electron configurations of iron porphyrins of all oxidation and spin states, π electron configuration of the porphyrin ring, synthesis of metal‐free porphyrins and other related macrocycles, insertion of iron into free‐base porphyrins and related macrocycles, the properties, reactions, uses and biological relevance of iron(0), ‐(I), ‐(II) porphyrins (the latter with S = 0, 1, and 2 spin state possibilities), of iron(II) porphyrin π‐cation radicals, of iron(III) porphyrins (with S = 1/2, 3/2, and 5/2 spin state possibilities), of iron(III) porphyrin and corrole π‐cation radicals, of iron(IV) porphyrins (including five‐ and six‐coordinate ferryl (FeO) 2+ , iron(IV) phenyl, carbene and hydrazine complexes, and the bis‐methoxide complex) and a comparison of iron(IV) porphyrins to iron(III) porphyrin π‐cation radicals, of iron(IV) porphyrin π‐cation radicals, and of the possible existence of iron(V) porphyrins. Included in the Fe(II) part are sections on addition of ligands to four‐coordinate iron(II) porphyrins, including equilibrium binding constants, photodissociation of ligands from PFeL 2 complexes, binding of small molecules (O 2 , CO, NO, HNO) to 5‐coordinate iron(II) porphyrins and design of porphyrin ligands that will mimic the active sites of heme proteins such as myoglobin and hemoglobin, the cytochromes P450 and nitric oxide synthases, and the nitrophorins and guanylyl cyclases. Included in the iron(III) part are sections on both 5‐ and 6‐coordinate high‐spin complexes and their similarities and differences, bridged or through‐space magnetically coupled complexes of high‐spin iron(III) porphyrins with other metal complexes as possible models for cytochrome oxidase and the assimilatory sulfite reductases, coupled oxidation of hemes by hydrogen peroxide or its equivalent, and the relationship of this reactivity to the reactions of heme oxygenase, iron(III) porphyrins as reduction catalysts, and photochemistry of iron(III) porphyrins, possible electron configurations of low‐spin iron(III) porphyrins, the phenomenon and possible electronic consequences of ruffling of the porphinato core in iron(III) porphyrins, the preferred orientation of planar axial ligands bound to low‐spin iron(III) porphyrins, NO complexes of iron(III) porphyrins, reduction potentials, equilibrium constants and rates of axial‐ligand addition and exchange, kinetics of axial‐ligand rotation and porphyrin ring inversion, kinetics of reduction and autoreduction of iron(III) porphyrins, electron self‐exchange between low‐spin iron(III) and iron(II) porphyrins, synthetic ferriheme proteins, and synthesis of five‐coordinate low‐spin iron(III) porphyrins having σ‐alkyl or σ‐aryl groups as axial ligands. The iron(IV) and iron(IV) cation radical sections discuss the high‐valent states of cytochromes P450 and related enzymes.

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