Stellacyanin structure

Thiobacillus ferrooxidans function. 6, 651 Rhus vernicifera stellacyanin structure, 6,651 Riboflavin 5 -phosphate zinc complexes, 5,958 Ribonucleotide reductases cobalt, 6,642 iron, 6,634... 

Intramolecular Ru(II) to Cu(II) ET rates have been measured in two other blue copper proteins, stellacyanin [42, 43] and azurin [9, 13, 28]. Pseudomonas aeruginosa azurin has been ruthenated at His83 [13] (Fig. 5). The intramolecular Ru(II) to Cu(II) ET rate of 1.9 s was found to be independent of temperature [28]. The Cu reorganization enthalpy was estimated to be < 7 kcal/mol [13, 28], a value confirming that blue copper is structured for efficient ET. Again, a blue copper ET rate is low in comparison with heme protein rates over similar distances (at similar driving forces) (Table 1). 

There are four other proteins - stellacyanin, rusticyanin, umecyanin and ami-cyanin (Table 3) which have been fairly extensively studied. A crystal structure determination for amicyanin from Thiobacillus versutus is now under way [61]. A number of other type 1 proteins have been identified. These include pseudo-... 

Spectra, but, in general, leaves the copper site the most exposed of the four cupredoxins. The sequence of Cbp is quite similar to that of stella-cyanin. Stellacyanin is a plant protein, also of unknown function, having visible spectra characteristic of type I copper, but lacking the methionine ligand found in all other type I proteins. A disulfide bond has been suggested as a potential copper ligand in stellacyanin the Cbp has both a methionine and the disulfide, so that prior to the structure determina-... 

The hyperfine shifts of groups bound to the donor atom are largely dominated by the contact interaction, even if pseudocontact shift contributions are sizable and any quantitative use of the shifts should rely on the separated contributions. Longitudinal nuclear relaxation times can be used, and have been used in the case of cobalt substitute stellacyanin, to determine metal-proton distances [101]. The contribution of Curie relaxation, estimated from the field dependence of the linewidths, can be used both for assignment and to determine structural constrains [101]. 

Hart PD et al (1996) A missing link in cupredoxins crystal structure of cucumber stellacyanin at 1.6 A resolution. Protein Sci 5 2175-2183 PDBID 1JER... 

Stellacyanin, the plastocyanins, and the azurins are the most widely studied copper-containing metalloproteins of the next active-site class, the Blue Copper sites. These proteins, which generally appear to be involved in redox chemistry, have quite unique spectral features32,33). The potential for complementary interaction between inorganic spectroscopy and protein crystallography is well demonstrated by the roles that they have played in generating fairly detailed geometric and electronic structural pictures of the Blue Copper metal centers. 

Cucumber stellacyanin and spinach plantacyanin are the only phyto-cyanins for which sequence information is currently available for both the mature proteins, determined by protein sequencing, and the precursor proteins, deduced from the cDNA (Mann et al., 1992, 1996 Nersissian et al., 1996, 1998). With the exception of the plantacyanins, most phyto-cyanins are chimeric proteins in their predicted or known mature forms. They are composed of two structurally distinct sequence domains, a 100-to 109-amino-acid BCB domain followed by a domain that varies in length between 30 and 220 amino acids, lacks any obvious consensus sequence, and resembles heavily glycosylated arabinogalactan proteins (AGP) (Nothnagel, 1997). 

Stellacyanin is also an important example of a heavily glycosylated protein for which the structure has been determined without its glyco components. It demonstrated that the carbohydrate moieties have virtually no effect on the folding topology of the polypeptide core of this particular glycoprotein. One of the three glycosylation sites in... 

At this writing, the three-dimensional sttuctures of eight different naturally occurring type 1 copper proteins are known. These include the cupredoxins plastocyanin at 1.33 A resolution (pdb code 1 PTC), azurin at 1.8 A (pdb code 2AZA), pseudoazurin at 1.55 A (pdb code IPAZ), amicyanin at 1.3 A (pdb code lAAC), auracyanin at 1.55 A (pdb code IQHQ), rusticyanin at 1.9 A (pdb code IRCY), and the phytocyanins cucumber basic protein at 1.8 A (pdb code2CBP), and stellacyanin at 1.6 A (pdb code IJER) Atomic coordinates for these and all other single-domain type 1 copper proteins are available from the Research Collaboratory for Structural Bioinformatics (RCSB) Protein Data Bank (PDB) and can be accessed online at www.rcsb.org/pdb/. 

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