1jhe: Difference between revisions

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[[Image:1jhe.jpg|left|200px]]<br /><applet load="1jhe" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1jhe.jpg|left|200px]]<br /><applet load="1jhe" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1jhe, resolution 2.5Å" />

'''LEXA L89P Q92W E152A K156A MUTANT'''<br />

==Overview==

LexA repressor undergoes a self-cleavage reaction. In vivo, this reaction, requires an activated form of RecA, but it occurs spontaneously in vitro, at high pH. Accordingly, LexA must both allow self-cleavage and yet, prevent this reaction in the absence of a stimulus. We have solved the, crystal structures of several mutant forms of LexA. Strikingly, two, distinct conformations are observed, one compatible with cleavage, and the, other in which the cleavage site is approximately 20 A from the catalytic, center. Our analysis provides insight into the structural and energetic, features that modulate the interconversion between these two forms and, hence the rate of the self-cleavage reaction. We suggest RecA activates, the self-cleavage of LexA and related proteins through selective, stabilization of the cleavable conformation.

LexA repressor undergoes a self-cleavage reaction. In vivo, this reaction requires an activated form of RecA, but it occurs spontaneously in vitro at high pH. Accordingly, LexA must both allow self-cleavage and yet prevent this reaction in the absence of a stimulus. We have solved the crystal structures of several mutant forms of LexA. Strikingly, two distinct conformations are observed, one compatible with cleavage, and the other in which the cleavage site is approximately 20 A from the catalytic center. Our analysis provides insight into the structural and energetic features that modulate the interconversion between these two forms and hence the rate of the self-cleavage reaction. We suggest RecA activates the self-cleavage of LexA and related proteins through selective stabilization of the cleavable conformation.

==About this Structure==

1JHE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/Repressor_lexA Repressor lexA], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.88 3.4.21.88] Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1JHE OCA].

1JHE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/Repressor_lexA Repressor lexA], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.88 3.4.21.88] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JHE OCA].

==Reference==

Line 14:

[[Category: Repressor lexA]]

[[Category: Single protein]]

[[Category: Little, J.W.]]

[[Category: Little, J W.]]

[[Category: Luo, Y.]]

[[Category: Mosimann, S.]]

[[Category: Pfuetzner, R.A.]]

[[Category: Pfuetzner, R A.]]

[[Category: Strynadka, N.C.J.]]

[[Category: Strynadka, N C.J.]]

[[Category: c-terminal]]

[[Category: lexa sos repressor]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Tue Nov 20 18~~:15:~~37 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:22:40 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1jhe.jpg|left|200px]]<br /><applet load="1jhe" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1jhe.jpg|left|200px]]<br /><applet load="1jhe" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1jhe, resolution 2.5&Aring;" />
 '''LEXA L89P Q92W E152A K156A MUTANT'''<br />
 ==Overview==
-LexA repressor undergoes a self-cleavage reaction. In vivo, this reaction, requires an activated form of RecA, but it occurs spontaneously in vitro, at high pH. Accordingly, LexA must both allow self-cleavage and yet, prevent this reaction in the absence of a stimulus. We have solved the, crystal structures of several mutant forms of LexA. Strikingly, two, distinct conformations are observed, one compatible with cleavage, and the, other in which the cleavage site is approximately 20 A from the catalytic, center. Our analysis provides insight into the structural and energetic, features that modulate the interconversion between these two forms and, hence the rate of the self-cleavage reaction. We suggest RecA activates, the self-cleavage of LexA and related proteins through selective, stabilization of the cleavable conformation.
+LexA repressor undergoes a self-cleavage reaction. In vivo, this reaction requires an activated form of RecA, but it occurs spontaneously in vitro at high pH. Accordingly, LexA must both allow self-cleavage and yet prevent this reaction in the absence of a stimulus. We have solved the crystal structures of several mutant forms of LexA. Strikingly, two distinct conformations are observed, one compatible with cleavage, and the other in which the cleavage site is approximately 20 A from the catalytic center. Our analysis provides insight into the structural and energetic features that modulate the interconversion between these two forms and hence the rate of the self-cleavage reaction. We suggest RecA activates the self-cleavage of LexA and related proteins through selective stabilization of the cleavable conformation.
 ==About this Structure==
-JHE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/Repressor_lexA Repressor lexA], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.88 3.4.21.88] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1JHE OCA].
+JHE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/Repressor_lexA Repressor lexA], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.88 3.4.21.88] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JHE OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Repressor lexA]]
 [[Category: Single protein]]
-[[Category: Little, J.W.]]
+[[Category: Little, J W.]]
 [[Category: Luo, Y.]]
 [[Category: Mosimann, S.]]
-[[Category: Pfuetzner, R.A.]]
+[[Category: Pfuetzner, R A.]]
-[[Category: Strynadka, N.C.J.]]
+[[Category: Strynadka, N C.J.]]
 [[Category: c-terminal]]
 [[Category: lexa sos repressor]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 18:15:37 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:22:40 2008''