3mba: Difference between revisions
New page: left|200px<br /><applet load="3mba" size="450" color="white" frame="true" align="right" spinBox="true" caption="3mba, resolution 2.0Å" /> '''APLYSIA LIMACINA MYOG... |
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[[Image:3mba.jpg|left|200px]]<br /><applet load="3mba" size=" | [[Image:3mba.jpg|left|200px]]<br /><applet load="3mba" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="3mba, resolution 2.0Å" /> | caption="3mba, resolution 2.0Å" /> | ||
'''APLYSIA LIMACINA MYOGLOBIN. CRYSTALLOGRAPHIC ANALYSIS AT 1.6 ANGSTROMS RESOLUTION'''<br /> | '''APLYSIA LIMACINA MYOGLOBIN. CRYSTALLOGRAPHIC ANALYSIS AT 1.6 ANGSTROMS RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
The crystal structure of the ferric form of myoglobin from the mollusc | The crystal structure of the ferric form of myoglobin from the mollusc Aplysia limacina has been refined at 1.6 A resolution, by restrained crystallographic refinement methods. The crystallographic R-factor is 0.19. The tertiary structure of the molecule conforms to the common globin fold, consisting of eight alpha-helices. The N-terminal helix A and helix G deviate significantly from linearity. The distal residue is recognized as Val63 (E7), which, however, does not contact the heme directly. Moreover the sixth (distal) co-ordination position of heme iron is not occupied by a water molecule at neutrality, i.e. below the acid-alkaline transition point of A. limacina myoglobin. The heme group sits in its crevice in the conventional orientation and no signs of heme isomerism are evident. The iron atom is 0.26 A out of the porphyrin plane, with a mean Fe-N (porphyrin) distance of 2.01 A. The co-ordination bond to the proximal histidine has a length of 2.05 A, and forms an angle of 4 degrees with the heme normal. A plane containing the imidazole ring of the proximal His intersects the heme at an angle of 29 degrees with the (porphyrin) 4N-2N direction. Inspection of the structure of pH 9.0 indicates that a hydroxyl ion is bound to the Fe sixth co-ordination position. | ||
==About this Structure== | ==About this Structure== | ||
3MBA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aplysia_limacina Aplysia limacina] with F, ACE and HEM as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 3MBA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aplysia_limacina Aplysia limacina] with <scene name='pdbligand=F:'>F</scene>, <scene name='pdbligand=ACE:'>ACE</scene> and <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3MBA OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: oxygen storage]] | [[Category: oxygen storage]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:10:15 2008'' |
Revision as of 20:10, 21 February 2008
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APLYSIA LIMACINA MYOGLOBIN. CRYSTALLOGRAPHIC ANALYSIS AT 1.6 ANGSTROMS RESOLUTION
OverviewOverview
The crystal structure of the ferric form of myoglobin from the mollusc Aplysia limacina has been refined at 1.6 A resolution, by restrained crystallographic refinement methods. The crystallographic R-factor is 0.19. The tertiary structure of the molecule conforms to the common globin fold, consisting of eight alpha-helices. The N-terminal helix A and helix G deviate significantly from linearity. The distal residue is recognized as Val63 (E7), which, however, does not contact the heme directly. Moreover the sixth (distal) co-ordination position of heme iron is not occupied by a water molecule at neutrality, i.e. below the acid-alkaline transition point of A. limacina myoglobin. The heme group sits in its crevice in the conventional orientation and no signs of heme isomerism are evident. The iron atom is 0.26 A out of the porphyrin plane, with a mean Fe-N (porphyrin) distance of 2.01 A. The co-ordination bond to the proximal histidine has a length of 2.05 A, and forms an angle of 4 degrees with the heme normal. A plane containing the imidazole ring of the proximal His intersects the heme at an angle of 29 degrees with the (porphyrin) 4N-2N direction. Inspection of the structure of pH 9.0 indicates that a hydroxyl ion is bound to the Fe sixth co-ordination position.
About this StructureAbout this Structure
3MBA is a Single protein structure of sequence from Aplysia limacina with , and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Aplysia limacina myoglobin. Crystallographic analysis at 1.6 A resolution., Bolognesi M, Onesti S, Gatti G, Coda A, Ascenzi P, Brunori M, J Mol Biol. 1989 Feb 5;205(3):529-44. PMID:2926816
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