1r0q

Characterization of the conversion of the malformed, recombinant cytochrome rc552 to a 2-formyl-4-vinyl (Spirographis) heme

spinqualitylabelsall models 1r0q, resolution 1.61Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1r0q is a 1 chain structure with sequence from Thermus thermophilus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.61Å Ligands: HFM Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CY552_THETH This monoheme basic protein appears to function as an electron donor to cytochrome oxidase in T.thermophilus. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Expression of the truncated (lacking an N-terminal signal sequence) structural gene of Thermus thermophilus cytochrome c(552) in the cytoplasm of Escherichia coli yields both dimeric (rC(557)) and monomeric (rC(552)) cytochrome c-like proteins [Keightley, J. A., et al. (1998) J. Biol. Chem. 273, 12006-12016], which form spontaneously without the involvement of cytochrome c maturation factors. Cytochrome rC(557) is comprised of a dimer and has been structurally characterized [McRee, D., et al. (2001) J. Biol. Chem. 276, 6537-6544]. Unexpectedly, the monomeric rC(552) transforms spontaneously to a cytochrome-like chromophore having, in its reduced state, the Q(oo) transition (alpha-band) at 572 nm (therefore called p572). The X-ray crystallographic structure of rC(552), at 1.41 A resolution, shows that the 2-vinyl group of heme ring I is converted to a [heme-CO-CH(2)-S-CH(2)-C(alpha)] conjugate with cysteine 11. Electron density maps obtained from isomorphous crystals of p572 at 1.61 A resolution reveal that the 2-vinyl group has been oxidized to a formyl group. This explains the lower energy of the Q(oo)() transition, the presence of a new, high-frequency band in the resonance Raman spectra at 1666 cm(-1) for oxidized and at 1646 cm(-1) for reduced samples, and the greatly altered, paramagnetically shifted (1)H NMR spectrum observed for this species. The overall process defines a novel mechanism for oxidation of the 2-vinyl group to a 2-formyl group and adds to the surprising array of chemical reactions that occur in the interaction of heme with the CXXCH sequence motif in apocytochromes c. Cytochrome rC552, formed during expression of the truncated, Thermus thermophilus cytochrome c552 gene in the cytoplasm of Escherichia coli, reacts spontaneously to form protein-bound 2-formyl-4-vinyl (Spirographis) heme.,Fee JA, Todaro TR, Luna E, Sanders D, Hunsicker-Wang LM, Patel KM, Bren KL, Gomez-Moran E, Hill MG, Ai J, Loehr TM, Oertling WA, Williams PA, Stout CD, McRee D, Pastuszyn A Biochemistry. 2004 Sep 28;43(38):12162-76. PMID:15379555 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome c nitrite reductase

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