Silver has long been used as an antimicrobial agent in general and medicinal use. Here, we observe that exposure of the Gram-positive, endospore-forming bacterium Bacillus subtilis to Ag(i) effects growth in a biphasic manner. In the first phase at Ag(i) concentrations below 50 μM B.
View Article and Find Full Text PDFThe synthesis of cytochrome c oxidase protein from Bacillus subtilis (i.e., BsSCO) binds copper with picomolar affinity, which increases the protein's melting temperature (i.
View Article and Find Full Text PDFSCO (ynthesis of ytochrome xidase) proteins are present in prokaryotic and eukaryotic cells, and are often required for efficient synthesis of the respiratory enzyme cytochrome oxidase. The version of SCO (SCO) has much greater affinity for Cu(II) than it does for Cu(I) (Davidson and Hill, 2009), and this has been contrasted to mitochondrial SCO proteins that are characterized as being specific for Cu(I) (Nittis, George and Winge, 2001). This differential affinity has been proposed to reflect the different physiological environments in which these two members of the SCO protein family reside.
View Article and Find Full Text PDFThe Synthesis of Cytochrome Oxidase protein, or SCO protein, is required for the assembly of cytochrome c oxidase in many mitochondrial and bacterial respiratory chains. SCOs have been proposed to deliver copper to the CuA site of cytochrome c oxidase. We have reported that Bacillus subtilis SCO (i.
View Article and Find Full Text PDFBiochim Biophys Acta
February 2012
The SCO protein from the aerobic bacterium Bacillus subtilis (BsSCO) is involved in the assembly of the cytochrome c oxidase complex, and specifically with the Cu(A) center. BsSCO has been proposed to play various roles in Cu(A) assembly including, the direct delivery of copper ions to the Cu(A) site, and/or maintaining the appropriate redox state of the cysteine ligands during formation of Cu(A). BsSCO binds copper in both Cu(II) and Cu(I) redox states, but has a million-fold higher affinity for Cu(II).
View Article and Find Full Text PDFSCO (synthesis of cytochrome c oxidase) proteins are involved in the assembly of the respiratory chain enzyme cytochrome c oxidase acting to assist in the assembly of the Cu(A) center contained within subunit II of the oxidase complex. The Cu(A) center receives electrons from the reductive substrate ferrocytochrome c, and passes them on to the cytochrome a center. Cytochrome a feeds electrons to the oxygen reaction site composed of cytochrome a(3) and Cu(B).
View Article and Find Full Text PDFBsSco is a member of the Sco protein family involved in the assembly of the Cu(A) center within cytochrome c oxidase. BsSco forms a complex with Cu(II) that has properties consistent with dithiolate ligation. Stopped-flow UV-visible absorbance and fluorescence coupled with multiwavelength analysis reveal biphasic binding kinetics between BsSco and Cu(II).
View Article and Find Full Text PDFMembers of the Sco protein family are implicated in the assembly of the respiratory complex cytochrome c oxidase. Several possible roles have been proposed for Sco: a copper delivery agent, a site-specific thiol reductase, and an indicator of cellular redox status. Two cysteine residues (C45 and C49) in the sequence CXXXCP and a histidine (H135) approximately 90 residues toward the C-terminus are conserved in Sco from bacteria, yeast, and humans.
View Article and Find Full Text PDFCytochrome caa3 from Bacillus subtilis is a member of the heme-copper oxidase family of integral membrane enzymes that includes mitochondrial cytochrome c oxidase. Subunit II of cytochrome caa3 has an extra 100 amino acids at its C-terminus, relative to its mitochondrial counterpart, and this extension encodes a heme C binding domain. Cytochrome caa3 has many of the properties of the complex formed between mitochondrial cytochrome c and mitochondrial cytochrome c oxidase.
View Article and Find Full Text PDFThe studies described here were performed to characterize further the plasma membrane associated protein BsSco, which is the product of the gene ypmQ, in Bacillus subtilis. BsSco is a member of the Sco family of proteins found in the inner mitochondrial membrane of yeast and humans and implicated as an accessory protein in the assembly of the Cu(A) site of cytochrome c oxidase. We have cloned the gene expressing BsSco, placed a six-histidine tag on its C-terminus, and over-expressed this protein in B.
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