1h97: Difference between revisions
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==Overview== | ==Overview== | ||
Monomeric hemoglobin from the trematode Paramphistomum epiclitum displays, very high oxygen affinity (P(50)<0.001 mm Hg) and an unusual heme distal, site containing tyrosyl residues at the B10 and E7 positions. The crystal, structure of aquo-met P. epiclitum hemoglobin, solved at 1.17 A resolution, via multiwavelength anomalous dispersion techniques (R-factor=0.121), shows that the heme distal site pocket residue TyrB10 is engaged in, hydrogen bonding to the iron-bound ligand. By contrast, residue TyrE7 is, unexpectedly locked next to the CD globin region, in a conformation, unsuitable for heme-bound ligand stabilisation. Such structural, organization of the E7 distal residue differs strikingly from that, observed in the nematode Ascaris suum hemoglobin (bearing TyrB10 and GlnE7, ... | Monomeric hemoglobin from the trematode Paramphistomum epiclitum displays, very high oxygen affinity (P(50)<0.001 mm Hg) and an unusual heme distal, site containing tyrosyl residues at the B10 and E7 positions. The crystal, structure of aquo-met P. epiclitum hemoglobin, solved at 1.17 A resolution, via multiwavelength anomalous dispersion techniques (R-factor=0.121), shows that the heme distal site pocket residue TyrB10 is engaged in, hydrogen bonding to the iron-bound ligand. By contrast, residue TyrE7 is, unexpectedly locked next to the CD globin region, in a conformation, unsuitable for heme-bound ligand stabilisation. Such structural, organization of the E7 distal residue differs strikingly from that, observed in the nematode Ascaris suum hemoglobin (bearing TyrB10 and GlnE7, residues), which also displays very high oxygen affinity. The oxygenation, and carbonylation parameters of wild-type P. epiclitum Hb as well as of, single- and double-site mutants, with residue substitutions at positions, B10, E7 and E11, have been determined and are discussed here in the light, of the protein atomic resolution crystal structure. | ||
==About this Structure== | ==About this Structure== | ||
1H97 is a | 1H97 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Paramphistomum_epiclitum Paramphistomum epiclitum] with SO4 and HEM as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Sites: HEA and HEB. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1H97 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: non-vertebrate hemoglobin]] | [[Category: non-vertebrate hemoglobin]] | ||
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Revision as of 16:19, 5 November 2007
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TREMATODE HEMOGLOBIN FROM PARAMPHISTOMUM EPICLITUM
OverviewOverview
Monomeric hemoglobin from the trematode Paramphistomum epiclitum displays, very high oxygen affinity (P(50)<0.001 mm Hg) and an unusual heme distal, site containing tyrosyl residues at the B10 and E7 positions. The crystal, structure of aquo-met P. epiclitum hemoglobin, solved at 1.17 A resolution, via multiwavelength anomalous dispersion techniques (R-factor=0.121), shows that the heme distal site pocket residue TyrB10 is engaged in, hydrogen bonding to the iron-bound ligand. By contrast, residue TyrE7 is, unexpectedly locked next to the CD globin region, in a conformation, unsuitable for heme-bound ligand stabilisation. Such structural, organization of the E7 distal residue differs strikingly from that, observed in the nematode Ascaris suum hemoglobin (bearing TyrB10 and GlnE7, residues), which also displays very high oxygen affinity. The oxygenation, and carbonylation parameters of wild-type P. epiclitum Hb as well as of, single- and double-site mutants, with residue substitutions at positions, B10, E7 and E11, have been determined and are discussed here in the light, of the protein atomic resolution crystal structure.
About this StructureAbout this Structure
1H97 is a Single protein structure of sequence from Paramphistomum epiclitum with SO4 and HEM as ligands. Structure known Active Sites: HEA and HEB. Full crystallographic information is available from OCA.
ReferenceReference
Very high resolution structure of a trematode hemoglobin displaying a TyrB10-TyrE7 heme distal residue pair and high oxygen affinity., Pesce A, Dewilde S, Kiger L, Milani M, Ascenzi P, Marden MC, Van Hauwaert ML, Vanfleteren J, Moens L, Bolognesi M, J Mol Biol. 2001 Jun 22;309(5):1153-64. PMID:11399085
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