1d06: Difference between revisions

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[[Image:1d06.gif|left|200px]]<br /><applet load="1d06" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1d06.gif|left|200px]]<br /><applet load="1d06" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1d06, resolution 1.4Å" />

'''STRUCTURAL BASIS OF DIMERIZATION AND SENSORY MECHANISMS OF OXYGEN-SENSING DOMAIN OF RHIZOBIUM MELILOTI FIXL DETERMINED AT 1.4A RESOLUTION'''<br />

==Overview==

FixL of Rhizobium meliloti (RmFixL) is a sensor histidine kinase of the, two-component system, which regulates the expression of the genes related, to nitrogen fixation in the root nodule in response to the O(2) levels., The crystal structure of the sensor domain of FixL (RmFixLH), which, contains a heme (Fe-porphyrin) as a sensing site, was determined at 1.4 A, resolution. Based on the structural and spectroscopic analyses, we propose, the O(2) sensing mechanism that differs from the case proposed in BjFixLH, as follows; conformational changes in the F/G loop, which are induced by, steric repulsion between the bent-bound O(2) and the Ile209 side-chain, would be transmitted to the histidine kinase domain. Interaction between, the iron-bound O(2) and Ile209 was also observed in the resonance Raman, spectra of RmFixLH as evidenced by the fact that the Fe-O(2) and Fe-CN, stretching frequencies were shifted from 575 to 570 cm(-1) (Fe-O(2)), and, 504 to 499 cm(-1), respectively, as the result of the replacement of, Ile209 with an Ala residue. In the I209A mutant of RmFixL, the O(2), sensing activity was destroyed, thus confirming our proposed mechanism.

FixL of Rhizobium meliloti (RmFixL) is a sensor histidine kinase of the two-component system, which regulates the expression of the genes related to nitrogen fixation in the root nodule in response to the O(2) levels. The crystal structure of the sensor domain of FixL (RmFixLH), which contains a heme (Fe-porphyrin) as a sensing site, was determined at 1.4 A resolution. Based on the structural and spectroscopic analyses, we propose the O(2) sensing mechanism that differs from the case proposed in BjFixLH as follows; conformational changes in the F/G loop, which are induced by steric repulsion between the bent-bound O(2) and the Ile209 side-chain, would be transmitted to the histidine kinase domain. Interaction between the iron-bound O(2) and Ile209 was also observed in the resonance Raman spectra of RmFixLH as evidenced by the fact that the Fe-O(2) and Fe-CN stretching frequencies were shifted from 575 to 570 cm(-1) (Fe-O(2)), and 504 to 499 cm(-1), respectively, as the result of the replacement of Ile209 with an Ala residue. In the I209A mutant of RmFixL, the O(2) sensing activity was destroyed, thus confirming our proposed mechanism.

==About this Structure==

1D06 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sinorhizobium_meliloti Sinorhizobium meliloti] with HEM as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1D06 OCA].

1D06 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sinorhizobium_meliloti Sinorhizobium meliloti] with <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D06 OCA].

==Reference==

Line 19:

[[Category: Nakamura, H.]]

[[Category: Nakamura, K.]]

[[Category: Park, S.Y.]]

[[Category: Park, S Y.]]

[[Category: Shiro, Y.]]

[[Category: Tamura, K.]]

Line 30:

[[Category: two-component system]]

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@@ Line 1: / Line 1: @@
-[[Image:1d06.gif|left|200px]]<br /><applet load="1d06" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1d06.gif|left|200px]]<br /><applet load="1d06" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1d06, resolution 1.4&Aring;" />
 '''STRUCTURAL BASIS OF DIMERIZATION AND SENSORY MECHANISMS OF OXYGEN-SENSING DOMAIN OF RHIZOBIUM MELILOTI FIXL DETERMINED AT 1.4A RESOLUTION'''<br />
 ==Overview==
-FixL of Rhizobium meliloti (RmFixL) is a sensor histidine kinase of the, two-component system, which regulates the expression of the genes related, to nitrogen fixation in the root nodule in response to the O(2) levels., The crystal structure of the sensor domain of FixL (RmFixLH), which, contains a heme (Fe-porphyrin) as a sensing site, was determined at 1.4 A, resolution. Based on the structural and spectroscopic analyses, we propose, the O(2) sensing mechanism that differs from the case proposed in BjFixLH, as follows; conformational changes in the F/G loop, which are induced by, steric repulsion between the bent-bound O(2) and the Ile209 side-chain, would be transmitted to the histidine kinase domain. Interaction between, the iron-bound O(2) and Ile209 was also observed in the resonance Raman, spectra of RmFixLH as evidenced by the fact that the Fe-O(2) and Fe-CN, stretching frequencies were shifted from 575 to 570 cm(-1) (Fe-O(2)), and, 504 to 499 cm(-1), respectively, as the result of the replacement of, Ile209 with an Ala residue. In the I209A mutant of RmFixL, the O(2), sensing activity was destroyed, thus confirming our proposed mechanism.
+FixL of Rhizobium meliloti (RmFixL) is a sensor histidine kinase of the two-component system, which regulates the expression of the genes related to nitrogen fixation in the root nodule in response to the O(2) levels. The crystal structure of the sensor domain of FixL (RmFixLH), which contains a heme (Fe-porphyrin) as a sensing site, was determined at 1.4 A resolution. Based on the structural and spectroscopic analyses, we propose the O(2) sensing mechanism that differs from the case proposed in BjFixLH as follows; conformational changes in the F/G loop, which are induced by steric repulsion between the bent-bound O(2) and the Ile209 side-chain, would be transmitted to the histidine kinase domain. Interaction between the iron-bound O(2) and Ile209 was also observed in the resonance Raman spectra of RmFixLH as evidenced by the fact that the Fe-O(2) and Fe-CN stretching frequencies were shifted from 575 to 570 cm(-1) (Fe-O(2)), and 504 to 499 cm(-1), respectively, as the result of the replacement of Ile209 with an Ala residue. In the I209A mutant of RmFixL, the O(2) sensing activity was destroyed, thus confirming our proposed mechanism.
 ==About this Structure==
-D06 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sinorhizobium_meliloti Sinorhizobium meliloti] with HEM as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1D06 OCA].
+D06 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sinorhizobium_meliloti Sinorhizobium meliloti] with <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D06 OCA].
 ==Reference==
@@ Line 19: / Line 19: @@
 [[Category: Nakamura, H.]]
 [[Category: Nakamura, K.]]
-[[Category: Park, S.Y.]]
+[[Category: Park, S Y.]]
 [[Category: Shiro, Y.]]
 [[Category: Tamura, K.]]
@@ Line 30: / Line 30: @@
 [[Category: two-component system]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 12:53:57 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:11:33 2008''