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1fev
From Proteopedia
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|PDB= 1fev |SIZE=350|CAPTION= <scene name='initialview01'>1fev</scene>, resolution 2.25Å | |PDB= 1fev |SIZE=350|CAPTION= <scene name='initialview01'>1fev</scene>, resolution 2.25Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=SO4:SULFATE ION'>SO4</scene> | + | |LIGAND= <scene name='pdbligand=AIB:ALPHA-AMINOISOBUTYRIC+ACID'>AIB</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Pancreatic_ribonuclease Pancreatic ribonuclease], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.27.5 3.1.27.5] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Pancreatic_ribonuclease Pancreatic ribonuclease], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.27.5 3.1.27.5] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1d5d|1D5D]], [[1d5e|1D5E]], [[1d5h|1D5H]], [[1rnv|1RNV]], [[1rbh|1RBH]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1fev FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1fev OCA], [http://www.ebi.ac.uk/pdbsum/1fev PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1fev RCSB]</span> | ||
}} | }} | ||
| Line 25: | Line 28: | ||
[[Category: Ratnaparkhi, G S.]] | [[Category: Ratnaparkhi, G S.]] | ||
[[Category: Varadarajan, R.]] | [[Category: Varadarajan, R.]] | ||
| - | [[Category: SO4]] | ||
[[Category: aib]] | [[Category: aib]] | ||
[[Category: alpha aminoisobutyric acid]] | [[Category: alpha aminoisobutyric acid]] | ||
| - | ''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 20:21:25 2008'' |
Revision as of 17:21, 30 March 2008
| |||||||
| , resolution 2.25Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Activity: | Pancreatic ribonuclease, with EC number 3.1.27.5 | ||||||
| Related: | 1D5D, 1D5E, 1D5H, 1RNV, 1RBH
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF THE ALA4AIB MUTATION IN RNASE S
Overview
The S protein-S peptide interaction is a model system to study binding thermodynamics in proteins. We substituted alanine at position 4 in S peptide by alpha-aminoisobutyric acid (Aib) to investigate the effect of this substitution on the conformation of free S peptide and on its binding to S protein. The thermodynamic consequences of this replacement were studied using isothermal titration calorimetry. The structures of the free and complexed peptides were studied using circular dichroic spectroscopy and X-ray crystallography, respectively. The alanine4Aib replacement stabilizes the free S peptide helix and does not perturb the tertiary structure of RNase S. Surprisingly, and in contrast to the wild-type S peptide, the DeltaG degrees of binding of peptide to S pro, over the temperature range 5-30 degrees C, is virtually independent of temperature. At 25 degrees C, the DeltaDeltaG degrees, DeltaDeltaH degrees, DeltaDeltaS and DeltaDeltaCp of binding are 0.7 kcal/mol, 2.8 kcal/mol, 6 kcal/mol x K and -60 kcal/mol x K, respectively. The positive value of DeltaDeltaS is probably due to a decrease in the entropy of uncomplexed alanine4Aib relative to the wild-type peptide. The positive value of DeltaDeltaH: degrees is unexpected and is probably due to favorable interactions formed in uncomplexed alanine4Aib. This study addresses the thermodynamic and structural consequences of a replacement of alanine by Aib both in the unfolded and complexed states in proteins.
About this Structure
1FEV is a Protein complex structure of sequences from Bos taurus. Full crystallographic information is available from OCA.
Reference
Structural and thermodynamic consequences of introducing alpha-aminoisobutyric acid in the S peptide of ribonuclease S., Ratnaparkhi GS, Awasthi SK, Rani P, Balaram P, Varadarajan R, Protein Eng. 2000 Oct;13(10):697-702. PMID:11112508
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