2iyn: Difference between revisions

Revision as of 08:05, 4 May 2008

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 Sun May 4 08:05:04 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]]
- {{Structure
+<!--
-|PDB= 2iyn |SIZE=350|CAPTION= <scene name='initialview01'>2iyn</scene>, resolution 2.08&Aring;
+The line below this paragraph, containing "STRUCTURE_2iyn", creates the "Structure Box" on the page.
-|SITE= <scene name='pdbsite=AC1:Mg+Binding+Site+For+Chain+C'>AC1</scene>
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY=
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_2iyn|  PDB=2iyn  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2iyn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2iyn OCA], [http://www.ebi.ac.uk/pdbsum/2iyn PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2iyn RCSB]</span>
-}}
 '''THE CO-FACTOR-INDUCED PRE-ACTIVE CONFORMATION IN PHOB'''
@@ Line 30: / Line 27: @@
 [[Category: Gomis-Ruth, F X.]]
 [[Category: Sola, M.]]
-[[Category: activation of the pho regulon]]
+[[Category: Activation of the pho regulon]]
-[[Category: activator]]
+[[Category: Activator]]
-[[Category: alpha/beta doubly wound fold]]
+[[Category: Alpha/beta doubly wound fold]]
-[[Category: dna- binding]]
+[[Category: Dna- binding]]
-[[Category: dna-binding]]
+[[Category: Dna-binding]]
-[[Category: gene regulation]]
+[[Category: Gene regulation]]
-[[Category: phosphate regulation]]
+[[Category: Phosphate regulation]]
-[[Category: phosphate transport]]
+[[Category: Phosphate transport]]
-[[Category: phosphorylation]]
+[[Category: Phosphorylation]]
-[[Category: sensory transduction]]
+[[Category: Sensory transduction]]
-[[Category: transcription]]
+[[Category: Transcription]]
-[[Category: transcription factor]]
+[[Category: Transcription factor]]
-[[Category: transcription regulation]]
+[[Category: Transcription regulation]]
-[[Category: transport]]
+[[Category: Transport]]
-[[Category: two-component regulatory system]]
+[[Category: Two-component regulatory system]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May  4 08:05:04 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 03:50:32 2008''