1bsq
From Proteopedia
(New page: 200px<br /><applet load="1bsq" size="450" color="white" frame="true" align="right" spinBox="true" caption="1bsq, resolution 2.22Å" /> '''STRUCTURAL AND FUNCT...) |
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| - | [[Image:1bsq.gif|left|200px]]<br /><applet load="1bsq" size=" | + | [[Image:1bsq.gif|left|200px]]<br /><applet load="1bsq" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1bsq, resolution 2.22Å" /> | caption="1bsq, resolution 2.22Å" /> | ||
'''STRUCTURAL AND FUNCTIONAL CONSEQUENCES OF POINT MUTATIONS OF VARIANTS A AND B OF BOVINE BETA-LACTOGLOBULIN'''<br /> | '''STRUCTURAL AND FUNCTIONAL CONSEQUENCES OF POINT MUTATIONS OF VARIANTS A AND B OF BOVINE BETA-LACTOGLOBULIN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of the trigonal crystal form of bovine beta-lactoglobulin | + | The structure of the trigonal crystal form of bovine beta-lactoglobulin variant B at pH 7.1 has been determined by X-ray diffraction methods at a resolution of 2.22 A and refined to values for R and Rfree of 0.239 and 0.286, respectively. By comparison with the structure of the trigonal crystal form of bovine beta-lactoglobulin variant A at pH 7.1, which was determined previously [Qin BY et al., 1998, Biochemistry 37:14014-14023], the structural consequences of the sequence differences D64G and V118A of variants A and B, respectively, have been investigated. Only minor differences in the core calyx structure occur. In the vicinity of the mutation site D64G on loop CD (residues 61-67), there are small changes in main-chain conformation, whereas the substitution V118A on beta-strand H is unaccompanied by changes in the surrounding structure, thereby creating a void volume and weakened hydrophobic interactions with a consequent loss of thermal stability relative to variant A. A conformational difference is found for the loop EF, implicated in the pH-dependent conformational change known as the Tanford transition, but it is not clear whether this reflects differences intrinsic to the variants in solution or differences in crystallization. |
==About this Structure== | ==About this Structure== | ||
| - | 1BSQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http:// | + | 1BSQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence 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=1BSQ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Baker, E | + | [[Category: Baker, E N.]] |
| - | [[Category: Bewley, M | + | [[Category: Bewley, M C.]] |
| - | [[Category: Creamer, L | + | [[Category: Creamer, L K.]] |
| - | [[Category: Jameson, G | + | [[Category: Jameson, G B.]] |
| - | [[Category: Qin, B | + | [[Category: Qin, B Y.]] |
[[Category: bovine beta-lactoglobulin]] | [[Category: bovine beta-lactoglobulin]] | ||
[[Category: crystal structure]] | [[Category: crystal structure]] | ||
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[[Category: point mutation]] | [[Category: point mutation]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:58:46 2008'' |
Revision as of 09:58, 21 February 2008
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STRUCTURAL AND FUNCTIONAL CONSEQUENCES OF POINT MUTATIONS OF VARIANTS A AND B OF BOVINE BETA-LACTOGLOBULIN
Overview
The structure of the trigonal crystal form of bovine beta-lactoglobulin variant B at pH 7.1 has been determined by X-ray diffraction methods at a resolution of 2.22 A and refined to values for R and Rfree of 0.239 and 0.286, respectively. By comparison with the structure of the trigonal crystal form of bovine beta-lactoglobulin variant A at pH 7.1, which was determined previously [Qin BY et al., 1998, Biochemistry 37:14014-14023], the structural consequences of the sequence differences D64G and V118A of variants A and B, respectively, have been investigated. Only minor differences in the core calyx structure occur. In the vicinity of the mutation site D64G on loop CD (residues 61-67), there are small changes in main-chain conformation, whereas the substitution V118A on beta-strand H is unaccompanied by changes in the surrounding structure, thereby creating a void volume and weakened hydrophobic interactions with a consequent loss of thermal stability relative to variant A. A conformational difference is found for the loop EF, implicated in the pH-dependent conformational change known as the Tanford transition, but it is not clear whether this reflects differences intrinsic to the variants in solution or differences in crystallization.
About this Structure
1BSQ is a Single protein structure of sequence from Bos taurus. Full crystallographic information is available from OCA.
Reference
Functional implications of structural differences between variants A and B of bovine beta-lactoglobulin., Qin BY, Bewley MC, Creamer LK, Baker EN, Jameson GB, Protein Sci. 1999 Jan;8(1):75-83. PMID:10210185
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