Periplasmic protein thiol:disulfide oxidoreductases of<i>Escherichia coli</i>

Fabianek, Renata A.; Hennecke, Hauke; Thöny‐Meyer, Linda

doi:10.1111/j.1574-6976.2000.tb00544.x

Cited by 130 publications

(63 citation statements)

References 134 publications

(275 reference statements)

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“…In E. coli, in addition to CcmA-H proteins, holocytochromes c formation required three periplasmic Dsb oxidoreductases (14). No orthologs of the thioredoxin CcmG or of the Dsb proteins could be identified in plant mitochondria.…”

Section: Discussionmentioning

confidence: 99%

“…Cysteine thiols of the heme-binding motif of apocytochromes c are oxidized by the periplasmic DsbA. CcmG, a thioredoxin-like protein, and CcmH, a putative thiol-disulfide oxidoreductase, reduce intramolecular disulfide bonds in apocytochromes before heme attachment by transferring electrons from the transmembrane disulfide oxidoreductase DsbD (DipZ) (14,15). In bacteria, the loss of CcmH (CycL͞Ccl2) results in either the absence of any detectable c-type cytochromes (2,6) or reduced levels of c-type cytochromes (16,17).…”

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confidence: 99%

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AtCCMH, an essential component of thec-type cytochrome maturation pathway inArabidopsismitochondria, interacts with apocytochromec

Meyer

Giegé

Gelhaye

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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The maturation of c-type cytochromes requires the covalent ligation of the heme cofactor to reduced cysteines of the CXXCH motif of apocytochromes. In contrast to mitochondria of other eukaryotes, plant mitochondria follow a pathway close to that found in ␣-and ␥-proteobacteria. We identified a nuclear-encoded protein, AtCCMH, the Arabidopsis thaliana ortholog of bacterial CcmH͞CycL proteins. In bacteria, CcmH and the thioredoxin CcmG are components of a periplasmic thio-reduction pathway proposed to maintain the apocytochrome c cysteines in a reduced state. AtCCMH is located exclusively in mitochondria. AtCCMH is an integral protein of the inner membrane with the conserved RCXXC motif facing the intermembrane space. Reduction assays show that the cysteine thiols in the RCXXC motif of AtCCMH can form a disulfide bond that can be reduced by enzymatic thiol reductants.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

AtCCMH, an essential component of thec-type cytochrome maturation pathway inArabidopsismitochondria, interacts with apocytochromec

Meyer

Giegé

Gelhaye

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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“…The requirement for redox chemistry in the context of in vivo cytochrome c assembly was appreciated through the discovery in bacteria of thiol-metabolizing components in systems I and II that constitute a transmembrane thio-reduction pathway (12)(13)(14). The components of this pathway include a sulfhydryldisulfide membrane transporter that conveys reducing power from the cytoplasm to the periplasmic space and a dedicated membrane-anchored thioredoxin that reduces the heme binding site of apocytochrome c prior to the heme attachment (13)(14)(15).…”

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confidence: 99%

“…The components of this pathway include a sulfhydryldisulfide membrane transporter that conveys reducing power from the cytoplasm to the periplasmic space and a dedicated membrane-anchored thioredoxin that reduces the heme binding site of apocytochrome c prior to the heme attachment (13)(14)(15).…”

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confidence: 99%

A Homolog of Prokaryotic Thiol Disulfide Transporter CcdA Is Required for the Assembly of the Cytochrome bf Complex in Arabidopsis Chloroplasts

Page¹,

Hamel²,

Gabilly³

et al. 2004

Journal of Biological Chemistry

101

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The c-type cytochromes are defined by the occurrence of heme covalently linked to the polypeptide via thioether bonds between heme and the cysteine sulfhydryls in the CXXCH motif of apocytochrome. Maintenance of apocytochrome sulfhydryls in a reduced state is a prerequisite for covalent ligation of heme to the CXXCH motif. In bacteria, a thiol disulfide transporter and a thioredoxin are two components in a thio-reduction pathway involved in c-type cytochrome assembly. We have identified in photosynthetic eukaryotes nucleus-encoded homologs of a prokaryotic thiol disulfide transporter, CcdA, which all display an N-terminal extension with respect to their bacterial counterparts. The extension of Arabidopsis CCDA functions as a targeting sequence, suggesting a plastid site of action for CCDA in eukaryotes. Using PhoA and LacZ as topological reporters, we established that Arabidopsis CCDA is a polytopic protein with within-membrane strictly conserved cysteine residues. Insertional mutants in the Arabidopsis CCDA gene were identified, and loss-of-function alleles were shown to impair photosynthesis because of a defect in cytochrome b 6 f accumulation, which we attribute to a block in the maturation of holocytochrome f, whose heme binding domain resides in the thylakoid lumen. We postulate that plastid cytochrome c maturation requires CCDA, thioredoxin HCF164, and other molecules in a membrane-associated trans-thylakoid thiol-reducing pathway.The c-type cytochromes are a virtually ubiquitous yet rather structurally diverse group of hemoproteins that reside on the so-called p-side 1 of the energy-transducing membrane systems where they function typically as electron carriers (1, 2). The c-type cytochromes are defined by the occurrence of heme covalently attached to the polypeptide via two thioether linkages between the vinyl groups of heme and the cysteine sulfhydryls in the apocytochrome (1, 3). A CXXCH 2 sequence in the apocytochrome provides the thiols for formation of the thioether bonds, and the imidazole of the histidine residue serves as one of the axial ligands of the heme. Remarkably, three distinct assembly pathways, referred to as systems I, II, and III, have emerged through genetic analysis of c-type cytochrome maturation in bacteria, chloroplasts, and mitochondria (for review, see Refs. 1 and 4 -7), an unexpected finding for what appears on the surface to be a rather simple chemical reaction (i.e. the addition of apocytochrome cysteine thiols to the vinyls of heme). Each system can be distinguished on the basis of a sequence relationship of specific assembly factors. Yet, there is an underlying assumption that the three systems are united by common biochemical requirements for holocytochrome c biogenesis (for review, see Refs. 2, 4, and 8). For instance, the need for reducing conditions appears to be inherent to the chemistry of thioether bond formation (4). Both substrates, apocytochrome c sulfhydryls and heme, need to be maintained reduced prior to the ligation of heme as indicated from in vitro and in o...

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“…Central to cytochrome c maturation (CCM) by systems I and II are several thiol-disulfide oxidoreductase proteins (4,7,8). Some of these are also shared with other disulfide bond-forming pathways of the periplasm and extracellular space where they are involved in disulfide bond formation, isomerization, and reduction (9)(10)(11)(12).…”

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confidence: 99%

Mechanism of substrate specificity in Bacillus subtilis ResA, a thioredoxin-like protein involved in cytochrome c maturation

Colbert¹,

Erbel

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

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The covalent attachment of heme cofactors to the apo-polypeptides via thioether bonds is unique to the maturation of c-type cytochromes. A number of thiol-disulfide oxidoreductases prepare the apocytochrome for heme insertion in system I and II cytochrome c maturation. Although most thiol-disulfide oxidoreductases are nonspecific, the less common, specific thiol-disulfide oxidoreductases may be key to directing the usage of electrons. Here we demonstrate that unlike other thiol-disulfide oxidoreductases, the protein responsible for reducing oxidized apocytochrome c in Bacillus subtilis, ResA, is specific for cytochrome c550 and utilizes alternate conformations to recognize redox partners. We report solution NMR evidence that ResA undergoes a redox-dependent conformational change between oxidation states, as well as data showing that ResA utilizes a surface cavity present only in the reduced state to recognize a peptide derived from cytochrome c550. Finally, we confirm that ResA is a specific thiol-disulfide oxidoreductase by comparing its reactivity to our mimetic peptide with its reactivity to oxidized glutathione, a nonspecific substrate. This study biochemically demonstrates the specificity of this thioldisulfide oxidoreductase and enables us to outline a structural mechanism of regulating the usage of electrons in a thiol-disulfide oxidoreductase system. NMR ͉ thiol-disulfide oxidoreductase ͉ x-ray crystallography

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Periplasmic protein thiol:disulfide oxidoreductases ofEscherichia coli

Cited by 130 publications

References 134 publications

AtCCMH, an essential component of thec-type cytochrome maturation pathway inArabidopsismitochondria, interacts with apocytochromec

AtCCMH, an essential component of thec-type cytochrome maturation pathway inArabidopsismitochondria, interacts with apocytochromec

A Homolog of Prokaryotic Thiol Disulfide Transporter CcdA Is Required for the Assembly of the Cytochrome bf Complex in Arabidopsis Chloroplasts

Mechanism of substrate specificity in Bacillus subtilis ResA, a thioredoxin-like protein involved in cytochrome c maturation

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