1lnw: Difference between revisions

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

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

caption="1lnw, resolution 2.10Å" />

'''CRYSTAL STRUCTURE OF THE MEXR REPRESSOR OF THE MEXAB-OPRM MULTIDRUG EFFLUX OPERON OF PSEUDOMONAS AERUGINOSA'''<br />

==Overview==

MexR is a member of the MarR family of bacterial transcriptional, regulators and is the repressor for the MexAB-OprM operon, which encodes a, tripartite multidrug efflux system in Pseudomonas aeruginosa. Mutations in, MexR result in increased resistance to multiple antibiotics due to, overexpression of this efflux system. We have determined the crystal, structure of MexR to 2.1-A resolution in the absence of effector. The four, copies of the MexR dimer in the asymmetric unit are observed in multiple, conformations. Analysis of these conformational states in the context of a, model of the MexR-DNA complex proposed in this study suggests that an, effector-induced conformational change may inhibit DNA binding by reducing, the spacing of the DNA binding domains. The inhibited conformation is, exhibited by one of the four MexR dimers, which contains an ordered, C-terminal tail from a neighboring monomer inserted between its DNA, binding domains and which we propose may resemble the MexR-effector, complex. Our results indicate that MexR may differ from the other, described member of this family, MarR, in the nature of its effector, mode, of DNA binding, and mechanism of regulation.

MexR is a member of the MarR family of bacterial transcriptional regulators and is the repressor for the MexAB-OprM operon, which encodes a tripartite multidrug efflux system in Pseudomonas aeruginosa. Mutations in MexR result in increased resistance to multiple antibiotics due to overexpression of this efflux system. We have determined the crystal structure of MexR to 2.1-A resolution in the absence of effector. The four copies of the MexR dimer in the asymmetric unit are observed in multiple conformations. Analysis of these conformational states in the context of a model of the MexR-DNA complex proposed in this study suggests that an effector-induced conformational change may inhibit DNA binding by reducing the spacing of the DNA binding domains. The inhibited conformation is exhibited by one of the four MexR dimers, which contains an ordered C-terminal tail from a neighboring monomer inserted between its DNA binding domains and which we propose may resemble the MexR-effector complex. Our results indicate that MexR may differ from the other described member of this family, MarR, in the nature of its effector, mode of DNA binding, and mechanism of regulation.

==About this Structure==

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

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

==Reference==

Line 13:

[[Category: Pseudomonas aeruginosa]]

[[Category: Single protein]]

[[Category: Lim, D.C.]]

[[Category: Lim, D C.]]

[[Category: Poole, K.]]

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

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

[[Category: dna binding protein]]

[[Category: mexr]]

Line 21:

[[Category: repressor]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Tue Nov 20 20~~:42:~~26 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:46:40 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1lnw.gif|left|200px]]<br /><applet load="1lnw" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1lnw.gif|left|200px]]<br /><applet load="1lnw" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1lnw, resolution 2.10&Aring;" />
 '''CRYSTAL STRUCTURE OF THE MEXR REPRESSOR OF THE MEXAB-OPRM MULTIDRUG EFFLUX OPERON OF PSEUDOMONAS AERUGINOSA'''<br />
 ==Overview==
-MexR is a member of the MarR family of bacterial transcriptional, regulators and is the repressor for the MexAB-OprM operon, which encodes a, tripartite multidrug efflux system in Pseudomonas aeruginosa. Mutations in, MexR result in increased resistance to multiple antibiotics due to, overexpression of this efflux system. We have determined the crystal, structure of MexR to 2.1-A resolution in the absence of effector. The four, copies of the MexR dimer in the asymmetric unit are observed in multiple, conformations. Analysis of these conformational states in the context of a, model of the MexR-DNA complex proposed in this study suggests that an, effector-induced conformational change may inhibit DNA binding by reducing, the spacing of the DNA binding domains. The inhibited conformation is, exhibited by one of the four MexR dimers, which contains an ordered, C-terminal tail from a neighboring monomer inserted between its DNA, binding domains and which we propose may resemble the MexR-effector, complex. Our results indicate that MexR may differ from the other, described member of this family, MarR, in the nature of its effector, mode, of DNA binding, and mechanism of regulation.
+MexR is a member of the MarR family of bacterial transcriptional regulators and is the repressor for the MexAB-OprM operon, which encodes a tripartite multidrug efflux system in Pseudomonas aeruginosa. Mutations in MexR result in increased resistance to multiple antibiotics due to overexpression of this efflux system. We have determined the crystal structure of MexR to 2.1-A resolution in the absence of effector. The four copies of the MexR dimer in the asymmetric unit are observed in multiple conformations. Analysis of these conformational states in the context of a model of the MexR-DNA complex proposed in this study suggests that an effector-induced conformational change may inhibit DNA binding by reducing the spacing of the DNA binding domains. The inhibited conformation is exhibited by one of the four MexR dimers, which contains an ordered C-terminal tail from a neighboring monomer inserted between its DNA binding domains and which we propose may resemble the MexR-effector complex. Our results indicate that MexR may differ from the other described member of this family, MarR, in the nature of its effector, mode of DNA binding, and mechanism of regulation.
 ==About this Structure==
-LNW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1LNW OCA].
+LNW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LNW OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Pseudomonas aeruginosa]]
 [[Category: Single protein]]
-[[Category: Lim, D.C.]]
+[[Category: Lim, D C.]]
 [[Category: Poole, K.]]
-[[Category: Strynadka, N.C.J.]]
+[[Category: Strynadka, N C.J.]]
 [[Category: dna binding protein]]
 [[Category: mexr]]
@@ Line 21: / Line 21: @@
 [[Category: repressor]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 20:42:26 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:46:40 2008''