1jti
From Proteopedia
(New page: 200px<br /><applet load="1jti" size="450" color="white" frame="true" align="right" spinBox="true" caption="1jti, resolution 2.30Å" /> '''Loop-inserted Struct...) |
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| - | [[Image:1jti.gif|left|200px]]<br /><applet load="1jti" size=" | + | [[Image:1jti.gif|left|200px]]<br /><applet load="1jti" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1jti, resolution 2.30Å" /> | caption="1jti, resolution 2.30Å" /> | ||
'''Loop-inserted Structure of P1-P1' Cleaved Ovalbumin Mutant R339T'''<br /> | '''Loop-inserted Structure of P1-P1' Cleaved Ovalbumin Mutant R339T'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Ovalbumin is a member of a superfamily of serine proteinase inhibitors, known as the serpins. It is, however, non-inhibitory towards serine | + | Ovalbumin is a member of a superfamily of serine proteinase inhibitors, known as the serpins. It is, however, non-inhibitory towards serine proteinases, and lacks the loop insertion mechanism common to the serpins due to unknown structural factors. Mutant ovalbumin, R339T, in which the P14 hinge residue is replaced, was produced and analyzed for its thermostability and three-dimensional structure. Differential scanning calorimetry revealed that the mutant ovalbumin, but not the wild-type protein, undergoes a marked thermostabilization (DeltaT(m)=15.8 degrees C) following the P1-P1' cleavage. Furthermore, the crystal structure, solved at 2.3 A resolution, clearly proved that the P1-P1' cleaved form assumes the fully loop-inserted conformation as seen in serpin that possess inhibitory activity. We therefore conclude that ovalbumin acquires the structural transition mechanism into the loop-inserted, thermostabilized form by the single hinge mutation. The mutant protein does not, however, possess inhibitory activity. The solved structure displays the occurrence of specific interactions that may prevent the smooth motion, relative to sheet A, of helices E and F and of the loop that follows helix F. These observations provide crucial insights into the question why R339T is still non-inhibitory. |
==About this Structure== | ==About this Structure== | ||
| - | 1JTI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus]. Full crystallographic information is available from [http:// | + | 1JTI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JTI OCA]. |
==Reference== | ==Reference== | ||
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[[Category: ovalbumin]] | [[Category: ovalbumin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:26:39 2008'' |
Revision as of 11:26, 21 February 2008
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Loop-inserted Structure of P1-P1' Cleaved Ovalbumin Mutant R339T
Overview
Ovalbumin is a member of a superfamily of serine proteinase inhibitors, known as the serpins. It is, however, non-inhibitory towards serine proteinases, and lacks the loop insertion mechanism common to the serpins due to unknown structural factors. Mutant ovalbumin, R339T, in which the P14 hinge residue is replaced, was produced and analyzed for its thermostability and three-dimensional structure. Differential scanning calorimetry revealed that the mutant ovalbumin, but not the wild-type protein, undergoes a marked thermostabilization (DeltaT(m)=15.8 degrees C) following the P1-P1' cleavage. Furthermore, the crystal structure, solved at 2.3 A resolution, clearly proved that the P1-P1' cleaved form assumes the fully loop-inserted conformation as seen in serpin that possess inhibitory activity. We therefore conclude that ovalbumin acquires the structural transition mechanism into the loop-inserted, thermostabilized form by the single hinge mutation. The mutant protein does not, however, possess inhibitory activity. The solved structure displays the occurrence of specific interactions that may prevent the smooth motion, relative to sheet A, of helices E and F and of the loop that follows helix F. These observations provide crucial insights into the question why R339T is still non-inhibitory.
About this Structure
1JTI is a Single protein structure of sequence from Gallus gallus. Full crystallographic information is available from OCA.
Reference
Loop-inserted and thermostabilized structure of P1-P1' cleaved ovalbumin mutant R339T., Yamasaki M, Arii Y, Mikami B, Hirose M, J Mol Biol. 2002 Jan 11;315(2):113-20. PMID:11779232
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