1qx8: Difference between revisions

Line 1:

[[Image:1qx8.gif|left|200px]]<br /><applet load="1qx8" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1qx8.gif|left|200px]]<br /><applet load="1qx8" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1qx8, resolution 2.02Å" />

'''Crystal structure of a five-residue deletion mutant of the Rop protein'''<br />

==Overview==

The repressor of primer (Rop) protein has become a steady source of, surprises concerning the relationship between the sequences and the, structures of several of its mutants and variants. Here we add another, piece to the puzzle of Rop by showing that an engineered deletion mutant, of the protein (corresponding to a deletion of residues 30-34 of the, wild-type protein and designed to restore the heptad periodicity at the, turn region) results in a complete reorganization of the bundle which is, converted from a homodimer to a homotetramer. In contrast (and as, previously shown), a two-residue insertion, which also restores the heptad, periodicity, is essentially identical with wild-type Rop. The new deletion, mutant structure is a canonical, left-handed, all-antiparallel bundle with, a completely different hydrophobic core and distinct surface properties., The structure agrees and qualitatively explains the results from, functional, thermodynamic, and kinetic studies which indicated that this, deletion mutant is a biologically inactive hyperstable homotetramer., Additional insight into the stability and dynamics of the mutant structure, has been obtained from extensive molecular dynamics simulations in, explicit water and with full treatment of electrostatics.

The repressor of primer (Rop) protein has become a steady source of surprises concerning the relationship between the sequences and the structures of several of its mutants and variants. Here we add another piece to the puzzle of Rop by showing that an engineered deletion mutant of the protein (corresponding to a deletion of residues 30-34 of the wild-type protein and designed to restore the heptad periodicity at the turn region) results in a complete reorganization of the bundle which is converted from a homodimer to a homotetramer. In contrast (and as previously shown), a two-residue insertion, which also restores the heptad periodicity, is essentially identical with wild-type Rop. The new deletion mutant structure is a canonical, left-handed, all-antiparallel bundle with a completely different hydrophobic core and distinct surface properties. The structure agrees and qualitatively explains the results from functional, thermodynamic, and kinetic studies which indicated that this deletion mutant is a biologically inactive hyperstable homotetramer. Additional insight into the stability and dynamics of the mutant structure has been obtained from extensive molecular dynamics simulations in explicit water and with full treatment of electrostatics.

==About this Structure==

1QX8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1QX8 OCA].

1QX8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QX8 OCA].

==Reference==

Line 14:

[[Category: Single protein]]

[[Category: Cesareni, G.]]

[[Category: Glykos, N.M.]]

[[Category: Glykos, N M.]]

[[Category: Kokkinidis, M.]]

[[Category: Kotsifaki, D.]]

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[[Category: replication; initiation of transcription; rna primer; x-ray]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Wed Nov~~ 21 01:05:~~18 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:44:40 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1qx8.gif|left|200px]]<br /><applet load="1qx8" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1qx8.gif|left|200px]]<br /><applet load="1qx8" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1qx8, resolution 2.02&Aring;" />
 '''Crystal structure of a five-residue deletion mutant of the Rop protein'''<br />
 ==Overview==
-The repressor of primer (Rop) protein has become a steady source of, surprises concerning the relationship between the sequences and the, structures of several of its mutants and variants. Here we add another, piece to the puzzle of Rop by showing that an engineered deletion mutant, of the protein (corresponding to a deletion of residues 30-34 of the, wild-type protein and designed to restore the heptad periodicity at the, turn region) results in a complete reorganization of the bundle which is, converted from a homodimer to a homotetramer. In contrast (and as, previously shown), a two-residue insertion, which also restores the heptad, periodicity, is essentially identical with wild-type Rop. The new deletion, mutant structure is a canonical, left-handed, all-antiparallel bundle with, a completely different hydrophobic core and distinct surface properties., The structure agrees and qualitatively explains the results from, functional, thermodynamic, and kinetic studies which indicated that this, deletion mutant is a biologically inactive hyperstable homotetramer., Additional insight into the stability and dynamics of the mutant structure, has been obtained from extensive molecular dynamics simulations in, explicit water and with full treatment of electrostatics.
+The repressor of primer (Rop) protein has become a steady source of surprises concerning the relationship between the sequences and the structures of several of its mutants and variants. Here we add another piece to the puzzle of Rop by showing that an engineered deletion mutant of the protein (corresponding to a deletion of residues 30-34 of the wild-type protein and designed to restore the heptad periodicity at the turn region) results in a complete reorganization of the bundle which is converted from a homodimer to a homotetramer. In contrast (and as previously shown), a two-residue insertion, which also restores the heptad periodicity, is essentially identical with wild-type Rop. The new deletion mutant structure is a canonical, left-handed, all-antiparallel bundle with a completely different hydrophobic core and distinct surface properties. The structure agrees and qualitatively explains the results from functional, thermodynamic, and kinetic studies which indicated that this deletion mutant is a biologically inactive hyperstable homotetramer. Additional insight into the stability and dynamics of the mutant structure has been obtained from extensive molecular dynamics simulations in explicit water and with full treatment of electrostatics.
 ==About this Structure==
-QX8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1QX8 OCA].
+QX8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QX8 OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Single protein]]
 [[Category: Cesareni, G.]]
-[[Category: Glykos, N.M.]]
+[[Category: Glykos, N M.]]
 [[Category: Kokkinidis, M.]]
 [[Category: Kotsifaki, D.]]
@@ Line 21: / Line 21: @@
 [[Category: replication; initiation of transcription; rna primer; x-ray]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 01:05:18 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:44:40 2008''