1r5q: Difference between revisions

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[[Image:1r5q.jpg|left|200px]]<br /><applet load="1r5q" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1r5q.jpg|left|200px]]<br /><applet load="1r5q" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1r5q, resolution 2.0Å" />

'''Crystal Structure Analysis of Kai A from PCC7120'''<br />

==Overview==

The cyanobacterial clock proteins KaiA and KaiB are proposed as regulators, of the circadian rhythm in cyanobacteria. Mutations in both proteins have, been reported to alter or abolish circadian rhythmicity. Here, we present, molecular models of both KaiA and KaiB from the cyanobacteria Anabaena sp, PCC7120 deduced by crystal structure analysis, and we discuss how, clock-changing or abolishing mutations may cause their resulting circadian, phenotype. The overall fold of the KaiA monomer is that of a four-helix, bundle. KaiB, on the other hand, adopts an alpha-beta meander motif. Both, proteins purify and crystallize as dimers. While the folds of the two, proteins are clearly different, their size and some surface features of, the physiologically relevant dimers are very similar. Notably, the, functionally relevant residues Arg 69 of KaiA and Arg 23 of KaiB align, well in space. The apparent structural similarities suggest that KaiA and, KaiB may compete for a potential common binding site on KaiC.

The cyanobacterial clock proteins KaiA and KaiB are proposed as regulators of the circadian rhythm in cyanobacteria. Mutations in both proteins have been reported to alter or abolish circadian rhythmicity. Here, we present molecular models of both KaiA and KaiB from the cyanobacteria Anabaena sp PCC7120 deduced by crystal structure analysis, and we discuss how clock-changing or abolishing mutations may cause their resulting circadian phenotype. The overall fold of the KaiA monomer is that of a four-helix bundle. KaiB, on the other hand, adopts an alpha-beta meander motif. Both proteins purify and crystallize as dimers. While the folds of the two proteins are clearly different, their size and some surface features of the physiologically relevant dimers are very similar. Notably, the functionally relevant residues Arg 69 of KaiA and Arg 23 of KaiB align well in space. The apparent structural similarities suggest that KaiA and KaiB may compete for a potential common binding site on KaiC.

==About this Structure==

1R5Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Anabaena_sp. Anabaena sp.]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1R5Q OCA].

1R5Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Anabaena_sp. Anabaena sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1R5Q OCA].

==Reference==

Line 13:

[[Category: Anabaena sp.]]

[[Category: Single protein]]

[[Category: Garces, R.G.]]

[[Category: Garces, R G.]]

[[Category: Gillon, W.]]

[[Category: Pai, E.F.]]

[[Category: Pai, E F.]]

[[Category: Wu, N.]]

[[Category: four-helix-bundle]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Wed Nov~~ 21 01:17:~~02 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:47:20 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1r5q.jpg|left|200px]]<br /><applet load="1r5q" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1r5q.jpg|left|200px]]<br /><applet load="1r5q" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1r5q, resolution 2.0&Aring;" />
 '''Crystal Structure Analysis of Kai A from PCC7120'''<br />
 ==Overview==
-The cyanobacterial clock proteins KaiA and KaiB are proposed as regulators, of the circadian rhythm in cyanobacteria. Mutations in both proteins have, been reported to alter or abolish circadian rhythmicity. Here, we present, molecular models of both KaiA and KaiB from the cyanobacteria Anabaena sp, PCC7120 deduced by crystal structure analysis, and we discuss how, clock-changing or abolishing mutations may cause their resulting circadian, phenotype. The overall fold of the KaiA monomer is that of a four-helix, bundle. KaiB, on the other hand, adopts an alpha-beta meander motif. Both, proteins purify and crystallize as dimers. While the folds of the two, proteins are clearly different, their size and some surface features of, the physiologically relevant dimers are very similar. Notably, the, functionally relevant residues Arg 69 of KaiA and Arg 23 of KaiB align, well in space. The apparent structural similarities suggest that KaiA and, KaiB may compete for a potential common binding site on KaiC.
+The cyanobacterial clock proteins KaiA and KaiB are proposed as regulators of the circadian rhythm in cyanobacteria. Mutations in both proteins have been reported to alter or abolish circadian rhythmicity. Here, we present molecular models of both KaiA and KaiB from the cyanobacteria Anabaena sp PCC7120 deduced by crystal structure analysis, and we discuss how clock-changing or abolishing mutations may cause their resulting circadian phenotype. The overall fold of the KaiA monomer is that of a four-helix bundle. KaiB, on the other hand, adopts an alpha-beta meander motif. Both proteins purify and crystallize as dimers. While the folds of the two proteins are clearly different, their size and some surface features of the physiologically relevant dimers are very similar. Notably, the functionally relevant residues Arg 69 of KaiA and Arg 23 of KaiB align well in space. The apparent structural similarities suggest that KaiA and KaiB may compete for a potential common binding site on KaiC.
 ==About this Structure==
-R5Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Anabaena_sp. Anabaena sp.]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1R5Q OCA].
+R5Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Anabaena_sp. Anabaena sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1R5Q OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Anabaena sp.]]
 [[Category: Single protein]]
-[[Category: Garces, R.G.]]
+[[Category: Garces, R G.]]
 [[Category: Gillon, W.]]
-[[Category: Pai, E.F.]]
+[[Category: Pai, E F.]]
 [[Category: Wu, N.]]
 [[Category: four-helix-bundle]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 01:17:02 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:47:20 2008''