1u2h
From Proteopedia
(New page: 200px<br /> <applet load="1u2h" size="450" color="white" frame="true" align="right" spinBox="true" caption="1u2h, resolution 0.96Å" /> '''X-ray Structure of ...) |
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| - | [[Image:1u2h.gif|left|200px]]<br /> | + | [[Image:1u2h.gif|left|200px]]<br /><applet load="1u2h" size="350" color="white" frame="true" align="right" spinBox="true" |
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caption="1u2h, resolution 0.96Å" /> | caption="1u2h, resolution 0.96Å" /> | ||
'''X-ray Structure of the N-terminally truncated human APEP-1'''<br /> | '''X-ray Structure of the N-terminally truncated human APEP-1'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: Human Aortic Preferentially Expressed Protein-1 (APEG-1) is a | + | BACKGROUND: Human Aortic Preferentially Expressed Protein-1 (APEG-1) is a novel specific smooth muscle differentiation marker thought to play a role in the growth and differentiation of arterial smooth muscle cells (SMCs). RESULTS: Good quality crystals that were suitable for X-ray crystallographic studies were obtained following the truncation of the 14 N-terminal amino acids of APEG-1, a region predicted to be disordered. The truncated protein (termed DeltaAPEG-1) consists of a single immunoglobulin (Ig) like domain which includes an Arg-Gly-Asp (RGD) adhesion recognition motif. The RGD motif is crucial for the interaction of extracellular proteins and plays a role in cell adhesion. The X-ray structure of DeltaAPEG-1 was determined and was refined to sub-atomic resolution (0.96 A). This is the best resolution for an immunoglobulin domain structure so far. The structure adopts a Greek-key beta-sandwich fold and belongs to the I (intermediate) set of the immunoglobulin superfamily. The residues lying between the beta-sheets form a hydrophobic core. The RGD motif folds into a 310 helix that is involved in the formation of a homodimer in the crystal which is mainly stabilized by salt bridges. Analytical ultracentrifugation studies revealed a moderate dissociation constant of 20 microM at physiological ionic strength, suggesting that APEG-1 dimerisation is only transient in the cell. The binding constant is strongly dependent on ionic strength. CONCLUSION: Our data suggests that the RGD motif might play a role not only in the adhesion of extracellular proteins but also in intracellular protein-protein interactions. However, it remains to be established whether the rather weak dimerisation of APEG-1 involving this motif is physiologically relevant. |
==About this Structure== | ==About this Structure== | ||
| - | 1U2H is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http:// | + | 1U2H is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1U2H OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Gotz, F.]] | [[Category: Gotz, F.]] | ||
[[Category: Heinemann, U.]] | [[Category: Heinemann, U.]] | ||
| - | [[Category: Manjasetty, B | + | [[Category: Manjasetty, B A.]] |
| - | [[Category: Niesen, F | + | [[Category: Niesen, F H.]] |
[[Category: Roske, Y.]] | [[Category: Roske, Y.]] | ||
[[Category: Scheich, C.]] | [[Category: Scheich, C.]] | ||
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[[Category: structural genomics]] | [[Category: structural genomics]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:19:55 2008'' |
Revision as of 13:19, 21 February 2008
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X-ray Structure of the N-terminally truncated human APEP-1
Overview
BACKGROUND: Human Aortic Preferentially Expressed Protein-1 (APEG-1) is a novel specific smooth muscle differentiation marker thought to play a role in the growth and differentiation of arterial smooth muscle cells (SMCs). RESULTS: Good quality crystals that were suitable for X-ray crystallographic studies were obtained following the truncation of the 14 N-terminal amino acids of APEG-1, a region predicted to be disordered. The truncated protein (termed DeltaAPEG-1) consists of a single immunoglobulin (Ig) like domain which includes an Arg-Gly-Asp (RGD) adhesion recognition motif. The RGD motif is crucial for the interaction of extracellular proteins and plays a role in cell adhesion. The X-ray structure of DeltaAPEG-1 was determined and was refined to sub-atomic resolution (0.96 A). This is the best resolution for an immunoglobulin domain structure so far. The structure adopts a Greek-key beta-sandwich fold and belongs to the I (intermediate) set of the immunoglobulin superfamily. The residues lying between the beta-sheets form a hydrophobic core. The RGD motif folds into a 310 helix that is involved in the formation of a homodimer in the crystal which is mainly stabilized by salt bridges. Analytical ultracentrifugation studies revealed a moderate dissociation constant of 20 microM at physiological ionic strength, suggesting that APEG-1 dimerisation is only transient in the cell. The binding constant is strongly dependent on ionic strength. CONCLUSION: Our data suggests that the RGD motif might play a role not only in the adhesion of extracellular proteins but also in intracellular protein-protein interactions. However, it remains to be established whether the rather weak dimerisation of APEG-1 involving this motif is physiologically relevant.
About this Structure
1U2H is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
X-ray structure of engineered human Aortic Preferentially Expressed Protein-1 (APEG-1)., Manjasetty BA, Niesen FH, Scheich C, Roske Y, Goetz F, Behlke J, Sievert V, Heinemann U, Bussow K, BMC Struct Biol. 2005 Dec 14;5:21. PMID:16354304
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