This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1eku
From Proteopedia
| Line 4: | Line 4: | ||
|PDB= 1eku |SIZE=350|CAPTION= <scene name='initialview01'>1eku</scene>, resolution 2.9Å | |PDB= 1eku |SIZE=350|CAPTION= <scene name='initialview01'>1eku</scene>, resolution 2.9Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=SO4:SULFATE ION'>SO4</scene> | + | |LIGAND= <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1eku FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1eku OCA], [http://www.ebi.ac.uk/pdbsum/1eku PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1eku RCSB]</span> | ||
}} | }} | ||
| Line 14: | Line 17: | ||
==Overview== | ==Overview== | ||
A mutant form of human interferon-gamma (IFN-gamma SC1) that binds one IFN-gamma receptor alpha chain (IFN-gamma R alpha) has been designed and characterized. IFN-gamma SC1 was derived by linking the two peptide chains of the IFN-gamma dimer by a seven-residue linker and changing His111 in the first chain to an aspartic acid residue. Isothermal titration calorimetry shows that IFN-gamma SC1 forms a 1:1 complex with its high-affinity receptor (IFN-gamma R alpha) with an affinity of 27(+/- 9) nM. The crystal structure of IFN-gamma SC1 has been determined at 2.9 A resolution from crystals grown in 1.4 M citrate solutions at pH 7.6. Comparison of the wild-type receptor-binding domain and the Asp111-containing domain of IFN-gamma SC1 show that they are structurally equivalent but have very different electrostatic surface potentials. As a result, surface charge rather than structural changes is likely responsible for the inability of the His111-->Asp domain of to bind IFN-gamma R alpha. The AB loops of IFN-gamma SC1 adopt conformations similar to the ordered loops of IFN-gamma observed in the crystal structure of the IFN-gamma/IFN-gamma R alpha complex. Thus, IFN-gamma R alpha binding does not result in a large conformational change in the AB loop as previously suggested. The structure also reveals the final six C-terminal amino acid residues of IFN-gamma SC1 (residues 253-258) that have not been observed in any other reported IFN-gamma structures. Despite binding to only one IFN-gamma R alpha, IFN-gamma SC1 is biologically active in cell proliferation, MHC class I induction, and anti-viral assays. This suggests that one domain of IFN-gamma is sufficient to recruit IFN-gamma R alpha and IFN-gamma R beta into a complex competent for eliciting biological activity. The current data are consistent with the main role of the IFN-gamma dimer being to decrease the dissociation constant of IFN-gamma for its cellular receptors. | A mutant form of human interferon-gamma (IFN-gamma SC1) that binds one IFN-gamma receptor alpha chain (IFN-gamma R alpha) has been designed and characterized. IFN-gamma SC1 was derived by linking the two peptide chains of the IFN-gamma dimer by a seven-residue linker and changing His111 in the first chain to an aspartic acid residue. Isothermal titration calorimetry shows that IFN-gamma SC1 forms a 1:1 complex with its high-affinity receptor (IFN-gamma R alpha) with an affinity of 27(+/- 9) nM. The crystal structure of IFN-gamma SC1 has been determined at 2.9 A resolution from crystals grown in 1.4 M citrate solutions at pH 7.6. Comparison of the wild-type receptor-binding domain and the Asp111-containing domain of IFN-gamma SC1 show that they are structurally equivalent but have very different electrostatic surface potentials. As a result, surface charge rather than structural changes is likely responsible for the inability of the His111-->Asp domain of to bind IFN-gamma R alpha. The AB loops of IFN-gamma SC1 adopt conformations similar to the ordered loops of IFN-gamma observed in the crystal structure of the IFN-gamma/IFN-gamma R alpha complex. Thus, IFN-gamma R alpha binding does not result in a large conformational change in the AB loop as previously suggested. The structure also reveals the final six C-terminal amino acid residues of IFN-gamma SC1 (residues 253-258) that have not been observed in any other reported IFN-gamma structures. Despite binding to only one IFN-gamma R alpha, IFN-gamma SC1 is biologically active in cell proliferation, MHC class I induction, and anti-viral assays. This suggests that one domain of IFN-gamma is sufficient to recruit IFN-gamma R alpha and IFN-gamma R beta into a complex competent for eliciting biological activity. The current data are consistent with the main role of the IFN-gamma dimer being to decrease the dissociation constant of IFN-gamma for its cellular receptors. | ||
| - | |||
| - | ==Disease== | ||
| - | Known diseases associated with this structure: AIDS, rapid progression to OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=147570 147570]], Aplastic anemia OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=147570 147570]], Hepatitis C virus, resistance to OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=147570 147570]], Interferon, immune, deficiency OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=147570 147570]], TSC2 angiomyolipomas, renal, modifier of OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=147570 147570]], Tuberculosis, susceptibility to OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=147570 147570]] | ||
==About this Structure== | ==About this Structure== | ||
| Line 31: | Line 31: | ||
[[Category: Parker, M H.]] | [[Category: Parker, M H.]] | ||
[[Category: Walter, M R.]] | [[Category: Walter, M R.]] | ||
| - | [[Category: SO4]] | ||
[[Category: cytokine]] | [[Category: cytokine]] | ||
[[Category: interferon]] | [[Category: interferon]] | ||
[[Category: protein engineering]] | [[Category: protein engineering]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 20:04:33 2008'' |
Revision as of 17:04, 30 March 2008
| |||||||
| , resolution 2.9Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF A BIOLOGICALLY ACTIVE SINGLE CHAIN MUTANT OF HUMAN IFN-GAMMA
Overview
A mutant form of human interferon-gamma (IFN-gamma SC1) that binds one IFN-gamma receptor alpha chain (IFN-gamma R alpha) has been designed and characterized. IFN-gamma SC1 was derived by linking the two peptide chains of the IFN-gamma dimer by a seven-residue linker and changing His111 in the first chain to an aspartic acid residue. Isothermal titration calorimetry shows that IFN-gamma SC1 forms a 1:1 complex with its high-affinity receptor (IFN-gamma R alpha) with an affinity of 27(+/- 9) nM. The crystal structure of IFN-gamma SC1 has been determined at 2.9 A resolution from crystals grown in 1.4 M citrate solutions at pH 7.6. Comparison of the wild-type receptor-binding domain and the Asp111-containing domain of IFN-gamma SC1 show that they are structurally equivalent but have very different electrostatic surface potentials. As a result, surface charge rather than structural changes is likely responsible for the inability of the His111-->Asp domain of to bind IFN-gamma R alpha. The AB loops of IFN-gamma SC1 adopt conformations similar to the ordered loops of IFN-gamma observed in the crystal structure of the IFN-gamma/IFN-gamma R alpha complex. Thus, IFN-gamma R alpha binding does not result in a large conformational change in the AB loop as previously suggested. The structure also reveals the final six C-terminal amino acid residues of IFN-gamma SC1 (residues 253-258) that have not been observed in any other reported IFN-gamma structures. Despite binding to only one IFN-gamma R alpha, IFN-gamma SC1 is biologically active in cell proliferation, MHC class I induction, and anti-viral assays. This suggests that one domain of IFN-gamma is sufficient to recruit IFN-gamma R alpha and IFN-gamma R beta into a complex competent for eliciting biological activity. The current data are consistent with the main role of the IFN-gamma dimer being to decrease the dissociation constant of IFN-gamma for its cellular receptors.
About this Structure
1EKU is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Design, characterization, and structure of a biologically active single-chain mutant of human IFN-gamma., Landar A, Curry B, Parker MH, DiGiacomo R, Indelicato SR, Nagabhushan TL, Rizzi G, Walter MR, J Mol Biol. 2000 May 26;299(1):169-79. PMID:10860730
Page seeded by OCA on Sun Mar 30 20:04:33 2008
