@article {6270,
	title = {Structure of a novel c7-type three-heme cytochrome domain from a multidomain cytochrome c polymer},
	journal = {Protein Science},
	volume = {13},
	year = {2004},
	pages = {1684-1692},
	abstract = {<p>The structure of a novel c7-type cytochrome domain that has two bishistidine coordinated hemes and one heme with histidine, methionine coordination (where the sixth ligand is a methionine residue) was determined at 1.7 {\r A} resolution. This domain is a representative of domains that form three polymers encoded by the Geobacter sulfurreducens genome. Two of these polymers consist of four and one protein of nine c7-type domains with a total of 12 and 27 hemes, respectively. Four individual domains (termed A, B, C, and D) from one such multiheme cytochrome c (ORF03300) were cloned and expressed in Escherichia coli. The domain C produced diffraction quality crystals from 2.4 M sodium malonate (pH 7). The structure was solved by MAD method and refined to an R-factor of 19.5\% and R-free of 21.8\%. Unlike the two c7 molecules with known structures, one from G. sulfurreducens (PpcA) and one from Desulfuromonas acetoxidans where all three hemes are bishistidine coordinated, this domain contains a heme which is coordinated by a methionine and a histidine residue. As a result, the corresponding heme could have a higher potential than the other two hemes. The apparent midpoint reduction potential, Eapp, of domain C is -105 mV, 50 mV higher than that of PpcA.</p>
},
	url = {http://onlinelibrary.wiley.com/doi/10.1110/ps.04626204/abstract},
	author = {Pokkuluri, P.R. and Londer, Yuri Y. and Norma E.C. Duke and Erickson, Jill and Miguel Pessanha and Salgueiro, C.A. and Schiffer, Marianne}
}
