1f44: Difference between revisions

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[[Image:1f44.gif|left|200px]]<br /><applet load="1f44" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1f44.gif|left|200px]]<br /><applet load="1f44" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1f44, resolution 2.05Å" />

'''CRYSTAL STRUCTURE OF TRIMERIC CRE RECOMBINASE-LOX COMPLEX'''<br />

==Overview==

The crystal structure of a novel Cre-Lox synapse was solved using phases, from multiple isomorphous replacement and anomalous scattering, and, refined to 2.05 A resolution. In this complex, a symmetric protein trimer, is bound to a Y-shaped three-way DNA junction, a marked departure from the, pseudo-4-fold symmetrical tetramer associated with Cre-mediated LoxP, recombination. The three-way DNA junction was accommodated by a simple, kink without significant distortion of the adjoining DNA duplexes., Although the mean angle between DNA arms in the Y and X structures was, similar, adjacent Cre trimer subunits rotated 29 degrees relative to those, in the tetramers. This rotation was accommodated at the protein-protein, and DNA-DNA interfaces by interactions that are "quasi-equivalent" to, those in the tetramer, analogous to packing differences of chemically, identical viral subunits at non-equivalent positions in icosahedral, capsids. This structural quasi-equivalence extends to function as Cre can, bind to, cleave and perform strand transfer with a three-way Lox, substrate. The structure explains the dual recognition of three and, four-way junctions by site-specific recombinases as being due to shared, structural features between the differently branched substrates and, plasticity of the protein-protein interfaces. To our knowledge, this is, the first direct demonstration of quasi-equivalence in both the assembly, and function of an oligomeric enzyme.

The crystal structure of a novel Cre-Lox synapse was solved using phases from multiple isomorphous replacement and anomalous scattering, and refined to 2.05 A resolution. In this complex, a symmetric protein trimer is bound to a Y-shaped three-way DNA junction, a marked departure from the pseudo-4-fold symmetrical tetramer associated with Cre-mediated LoxP recombination. The three-way DNA junction was accommodated by a simple kink without significant distortion of the adjoining DNA duplexes. Although the mean angle between DNA arms in the Y and X structures was similar, adjacent Cre trimer subunits rotated 29 degrees relative to those in the tetramers. This rotation was accommodated at the protein-protein and DNA-DNA interfaces by interactions that are "quasi-equivalent" to those in the tetramer, analogous to packing differences of chemically identical viral subunits at non-equivalent positions in icosahedral capsids. This structural quasi-equivalence extends to function as Cre can bind to, cleave and perform strand transfer with a three-way Lox substrate. The structure explains the dual recognition of three and four-way junctions by site-specific recombinases as being due to shared structural features between the differently branched substrates and plasticity of the protein-protein interfaces. To our knowledge, this is the first direct demonstration of quasi-equivalence in both the assembly and function of an oligomeric enzyme.

==About this Structure==

1F44 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_p21 Enterobacteria phage p21]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1F44 OCA].

1F44 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_p21 Enterobacteria phage p21]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F44 OCA].

==Reference==

Line 13:

[[Category: Enterobacteria phage p21]]

[[Category: Single protein]]

[[Category: Baldwin, E.P.]]

[[Category: Baldwin, E P.]]

[[Category: Woods, K.C.]]

[[Category: Woods, K C.]]

[[Category: branched dna]]

[[Category: hydrolase]]

Line 25:

[[Category: y-junction]]

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@@ Line 1: / Line 1: @@
-[[Image:1f44.gif|left|200px]]<br /><applet load="1f44" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1f44.gif|left|200px]]<br /><applet load="1f44" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1f44, resolution 2.05&Aring;" />
 '''CRYSTAL STRUCTURE OF TRIMERIC CRE RECOMBINASE-LOX COMPLEX'''<br />
 ==Overview==
-The crystal structure of a novel Cre-Lox synapse was solved using phases, from multiple isomorphous replacement and anomalous scattering, and, refined to 2.05 A resolution. In this complex, a symmetric protein trimer, is bound to a Y-shaped three-way DNA junction, a marked departure from the, pseudo-4-fold symmetrical tetramer associated with Cre-mediated LoxP, recombination. The three-way DNA junction was accommodated by a simple, kink without significant distortion of the adjoining DNA duplexes., Although the mean angle between DNA arms in the Y and X structures was, similar, adjacent Cre trimer subunits rotated 29 degrees relative to those, in the tetramers. This rotation was accommodated at the protein-protein, and DNA-DNA interfaces by interactions that are "quasi-equivalent" to, those in the tetramer, analogous to packing differences of chemically, identical viral subunits at non-equivalent positions in icosahedral, capsids. This structural quasi-equivalence extends to function as Cre can, bind to, cleave and perform strand transfer with a three-way Lox, substrate. The structure explains the dual recognition of three and, four-way junctions by site-specific recombinases as being due to shared, structural features between the differently branched substrates and, plasticity of the protein-protein interfaces. To our knowledge, this is, the first direct demonstration of quasi-equivalence in both the assembly, and function of an oligomeric enzyme.
+The crystal structure of a novel Cre-Lox synapse was solved using phases from multiple isomorphous replacement and anomalous scattering, and refined to 2.05 A resolution. In this complex, a symmetric protein trimer is bound to a Y-shaped three-way DNA junction, a marked departure from the pseudo-4-fold symmetrical tetramer associated with Cre-mediated LoxP recombination. The three-way DNA junction was accommodated by a simple kink without significant distortion of the adjoining DNA duplexes. Although the mean angle between DNA arms in the Y and X structures was similar, adjacent Cre trimer subunits rotated 29 degrees relative to those in the tetramers. This rotation was accommodated at the protein-protein and DNA-DNA interfaces by interactions that are "quasi-equivalent" to those in the tetramer, analogous to packing differences of chemically identical viral subunits at non-equivalent positions in icosahedral capsids. This structural quasi-equivalence extends to function as Cre can bind to, cleave and perform strand transfer with a three-way Lox substrate. The structure explains the dual recognition of three and four-way junctions by site-specific recombinases as being due to shared structural features between the differently branched substrates and plasticity of the protein-protein interfaces. To our knowledge, this is the first direct demonstration of quasi-equivalence in both the assembly and function of an oligomeric enzyme.
 ==About this Structure==
-F44 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_p21 Enterobacteria phage p21]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1F44 OCA].
+F44 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_p21 Enterobacteria phage p21]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F44 OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Enterobacteria phage p21]]
 [[Category: Single protein]]
-[[Category: Baldwin, E.P.]]
+[[Category: Baldwin, E P.]]
-[[Category: Woods, K.C.]]
+[[Category: Woods, K C.]]
 [[Category: branched dna]]
 [[Category: hydrolase]]
@@ Line 25: / Line 25: @@
 [[Category: y-junction]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 14:35:28 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:34:40 2008''