2iyn: Difference between revisions

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, resolution 2.08Å

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THE CO-FACTOR-INDUCED PRE-ACTIVE CONFORMATION IN PHOB

OverviewOverview

PhoB is an Escherichia coli transcription factor from a two-component signal transduction system that is sensitive to limiting environmental phosphate conditions. It consists of an N-terminal receiver domain (RD) and a C-terminal DNA-binding domain. The protein is activated upon phosphorylation at the RD, an event that depends on Mg(2+) binding. The structure of PhoB RD in complex with Mg(2+) is presented, which shows three protomers in the asymmetric unit that interact across two different surfaces. One association is symmetric and has been described as a non-active dimerization contact; the other involves the alpha4-beta5-alpha5 interface and recalls the contact found in activated PhoB. However, here this last interaction is not perfectly symmetric and helix alpha4, which in the activated molecule undergoes a helical shift, becomes strongly destabilized in one of the interacting monomers. All protomers bind the cation in a similar manner but, interestingly, at the prospective binding site for the phosphate moiety the side chains of either Glu88 (in helix alpha4) or Trp54 alternate and interact with active-site atoms. When Glu88 is inside the cavity, helix alpha4 is arranged similarly to the unliganded wild-type structure. However, if Trp54 is present, the helix loses its contacts with the active-site cavity and vanishes. Accordingly, the presence of Trp54 in the active site induces a flexible state in helix alpha4, potentially allowing a helical shift that phosphorylation would eventually stabilize.

About this StructureAbout this Structure

2IYN is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

ReferenceReference

The cofactor-induced pre-active conformation in PhoB., Sola M, Drew DL, Blanco AG, Gomis-Ruth FX, Coll M, Acta Crystallogr D Biol Crystallogr. 2006 Sep;62(Pt 9):1046-57. Epub 2006, Aug 19. PMID:16929106

Page seeded by OCA on Thu Mar 20 17:35:05 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
-[[Image:2iyn.gif|left|200px]]<br /><applet load="2iyn" size="350" color="white" frame="true" align="right" spinBox="true"
+[[Image:2iyn.gif|left|200px]]
-caption="2iyn, resolution 2.08&Aring;" />
-'''THE CO-FACTOR-INDUCED PRE-ACTIVE CONFORMATION IN PHOB'''<br />
+ {{Structure
+|PDB= 2iyn |SIZE=350|CAPTION= <scene name='initialview01'>2iyn</scene>, resolution 2.08&Aring;
+|SITE= <scene name='pdbsite=AC1:Mg+Binding+Site+For+Chain+C'>AC1</scene>
+|LIGAND= <scene name='pdbligand=MG:MAGNESIUM ION'>MG</scene>
+|ACTIVITY=
+|GENE=
+}}
+'''THE CO-FACTOR-INDUCED PRE-ACTIVE CONFORMATION IN PHOB'''
 ==Overview==
@@ Line 7: / Line 16: @@
 ==About this Structure==
-IYN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=MG:'>MG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Known structural/functional Site: <scene name='pdbsite=AC1:Mg+Binding+Site+For+Chain+C'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IYN OCA].
+IYN is a [[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=2IYN OCA].
 ==Reference==
-The cofactor-induced pre-active conformation in PhoB., Sola M, Drew DL, Blanco AG, Gomis-Ruth FX, Coll M, Acta Crystallogr D Biol Crystallogr. 2006 Sep;62(Pt 9):1046-57. Epub 2006, Aug 19. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=16929106 16929106]
+The cofactor-induced pre-active conformation in PhoB., Sola M, Drew DL, Blanco AG, Gomis-Ruth FX, Coll M, Acta Crystallogr D Biol Crystallogr. 2006 Sep;62(Pt 9):1046-57. Epub 2006, Aug 19. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16929106 16929106]
 [[Category: Escherichia coli]]
 [[Category: Single protein]]
@@ Line 35: / Line 44: @@
 [[Category: two-component regulatory system]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:57:31 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 17:35:05 2008''