1mdc: Difference between revisions
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[[Image:1mdc.gif|left|200px]]<br /><applet load="1mdc" size=" | [[Image:1mdc.gif|left|200px]]<br /><applet load="1mdc" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1mdc, resolution 1.75Å" /> | caption="1mdc, resolution 1.75Å" /> | ||
'''CRYSTALLIZATION, STRUCTURE DETERMINATION AND LEAST-SQUARES REFINEMENT TO 1.75 ANGSTROMS RESOLUTION OF THE FATTY-ACID-BINDING PROTEIN ISOLATED FROM MANDUCA SEXTA L'''<br /> | '''CRYSTALLIZATION, STRUCTURE DETERMINATION AND LEAST-SQUARES REFINEMENT TO 1.75 ANGSTROMS RESOLUTION OF THE FATTY-ACID-BINDING PROTEIN ISOLATED FROM MANDUCA SEXTA L'''<br /> | ||
==Overview== | ==Overview== | ||
The molecular structure of an insect fatty-acid-binding protein isolated | The molecular structure of an insect fatty-acid-binding protein isolated from Manduca sexta L. has been determined and refined to a nominal resolution of 1.75 A. Crystals used in the investigation were grown from 1.6 M-ammonium sulfate solutions buffered at pH 4.5 with 50 mM-sodium succinate, and belonged to space group P2(1) with unit cell dimensions of a = 27.5 A, b = 71.0 A, c = 28.7 A and beta = 90.8 degrees. An electron density map, phased with four heavy-atom derivatives and calculated to 2.5 A resolution, allowed for complete tracing of the 131 amino acid residue polypeptide chain. Subsequent least-squares refinement of the model reduced the R-factor from 46.0% to 17.3% using all measured X-ray data from 30.0 A to 1.75 A. Approximately 92% of the amino acid residues fall into classical secondary structural elements including ten strands of anti-parallel beta-pleated sheet, two alpha-helices, one type I turn, three type II turns, four type II' turns and one type III turn. As in other fatty-acid-binding proteins, the overall molecular architecture of the insect molecule consists of ten strands of anti-parallel beta-pleated sheet forming two layers that are nearly orthogonal to one another. A helix-turn-helix motif at the N-terminal portion of the protein flanks one side of the up-and-down beta-barrel. The functional group of the fatty acid is within hydrogen-bonding distance of Gln39, Tyr129, Arg127 and a sulfate molecule, while the aliphatic portion of the ligand is surrounded by hydrophobic amino acid residues lining the beta-barrel. The binding of the carboxylic acid portion of the ligand is very similar to that observed in P2 myelin protein and the murine adipocyte lipid-binding protein, but the positioning of the hydrocarbon tail after approximately C6 is completely different. | ||
==About this Structure== | ==About this Structure== | ||
1MDC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Manduca_sexta Manduca sexta] with SO4, ACE and PLM as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1MDC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Manduca_sexta Manduca sexta] with <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=ACE:'>ACE</scene> and <scene name='pdbligand=PLM:'>PLM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MDC OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Benning, M.]] | [[Category: Benning, M.]] | ||
[[Category: Holden, H | [[Category: Holden, H M.]] | ||
[[Category: ACE]] | [[Category: ACE]] | ||
[[Category: PLM]] | [[Category: PLM]] | ||
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[[Category: binding protein]] | [[Category: binding protein]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:54:06 2008'' |
Revision as of 14:54, 21 February 2008
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CRYSTALLIZATION, STRUCTURE DETERMINATION AND LEAST-SQUARES REFINEMENT TO 1.75 ANGSTROMS RESOLUTION OF THE FATTY-ACID-BINDING PROTEIN ISOLATED FROM MANDUCA SEXTA L
OverviewOverview
The molecular structure of an insect fatty-acid-binding protein isolated from Manduca sexta L. has been determined and refined to a nominal resolution of 1.75 A. Crystals used in the investigation were grown from 1.6 M-ammonium sulfate solutions buffered at pH 4.5 with 50 mM-sodium succinate, and belonged to space group P2(1) with unit cell dimensions of a = 27.5 A, b = 71.0 A, c = 28.7 A and beta = 90.8 degrees. An electron density map, phased with four heavy-atom derivatives and calculated to 2.5 A resolution, allowed for complete tracing of the 131 amino acid residue polypeptide chain. Subsequent least-squares refinement of the model reduced the R-factor from 46.0% to 17.3% using all measured X-ray data from 30.0 A to 1.75 A. Approximately 92% of the amino acid residues fall into classical secondary structural elements including ten strands of anti-parallel beta-pleated sheet, two alpha-helices, one type I turn, three type II turns, four type II' turns and one type III turn. As in other fatty-acid-binding proteins, the overall molecular architecture of the insect molecule consists of ten strands of anti-parallel beta-pleated sheet forming two layers that are nearly orthogonal to one another. A helix-turn-helix motif at the N-terminal portion of the protein flanks one side of the up-and-down beta-barrel. The functional group of the fatty acid is within hydrogen-bonding distance of Gln39, Tyr129, Arg127 and a sulfate molecule, while the aliphatic portion of the ligand is surrounded by hydrophobic amino acid residues lining the beta-barrel. The binding of the carboxylic acid portion of the ligand is very similar to that observed in P2 myelin protein and the murine adipocyte lipid-binding protein, but the positioning of the hydrocarbon tail after approximately C6 is completely different.
About this StructureAbout this Structure
1MDC is a Single protein structure of sequence from Manduca sexta with , and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Crystallization, structure determination and least-squares refinement to 1.75 A resolution of the fatty-acid-binding protein isolated from Manduca sexta L., Benning MM, Smith AF, Wells MA, Holden HM, J Mol Biol. 1992 Nov 5;228(1):208-19. PMID:1447782
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