1fev: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1fev.gif|left|200px]] | [[Image:1fev.gif|left|200px]] | ||
'''CRYSTAL STRUCTURE OF THE ALA4AIB MUTATION IN RNASE S''' | {{Structure | ||
|PDB= 1fev |SIZE=350|CAPTION= <scene name='initialview01'>1fev</scene>, resolution 2.25Å | |||
|SITE= | |||
|LIGAND= <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] | |||
|GENE= | |||
}} | |||
'''CRYSTAL STRUCTURE OF THE ALA4AIB MUTATION IN RNASE S''' | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
1FEV is a [ | 1FEV is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FEV OCA]. | ||
==Reference== | ==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:[http:// | 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:[http://www.ncbi.nlm.nih.gov/pubmed/11112508 11112508] | ||
[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Pancreatic ribonuclease]] | [[Category: Pancreatic ribonuclease]] | ||
| Line 20: | Line 29: | ||
[[Category: alpha aminoisobutyric acid]] | [[Category: alpha aminoisobutyric acid]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:08:11 2008'' | ||
Revision as of 12:08, 20 March 2008
| |||||||
| , resolution 2.25Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Activity: | Pancreatic ribonuclease, with EC number 3.1.27.5 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF THE ALA4AIB MUTATION IN RNASE S
OverviewOverview
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 StructureAbout this Structure
1FEV is a Protein complex structure of sequences from Bos taurus. Full crystallographic information is available from OCA.
ReferenceReference
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
Page seeded by OCA on Thu Mar 20 11:08:11 2008