2ft7: Difference between revisions

Revision as of 04:17, 4 May 2008

Structure of Cu(I)azurin at pH 6, with the metal-binding loop sequence "CTFPGHSALM" replaced with "CTPHPM"

OverviewOverview

The main active-site loop of the copper-binding protein azurin (a cupredoxin) has been shortened from C(112)TFPGH(117)SALM(121) to C(112)TPH(115)PFM(118) (the native loop from the cupredoxin amicyanin) and also to C(112)TPH(115)PM(117). The Cu(II) site structure is almost unaffected by shortening, as is that of the Cu(I) center at alkaline pH in the variant with the C(112)TPH(115)PM(117) loop sequence. Subtle spectroscopic differences due to alterations in the spin density distribution at the Cu(II) site can be attributed mainly to changes in the hydrogen-bonding pattern. Electron transfer is almost unaffected by the introduction of the C(112)TPH(115)PFM(118) loop, but removal of the Phe residue has a sizable effect on reactivity, probably because of diminished homodimer formation. At mildly acidic pH values, the His-115 ligand protonates and dissociates from the cuprous ion, an effect that has a dramatic influence on the reactivity of cupredoxins. These studies demonstrate that the amicyanin loop adopts a conformation identical to that found in the native protein when introduced into azurin, that a shorter than naturally occurring C-terminal active-site loop can support a functional T1 copper site, that CTPHPM is the minimal loop length required for binding this ubiquitous electron transfer center, and that the length and sequence of a metal-binding loop regulates a range of structural and functional features of the active site of a metalloprotein.

About this StructureAbout this Structure

2FT7 is a Single protein structure of sequence from Pseudomonas aeruginosa. Full crystallographic information is available from OCA.

ReferenceReference

Basic requirements for a metal-binding site in a protein: the influence of loop shortening on the cupredoxin azurin., Li C, Yanagisawa S, Martins BM, Messerschmidt A, Banfield MJ, Dennison C, Proc Natl Acad Sci U S A. 2006 May 9;103(19):7258-63. Epub 2006 May 1. PMID:16651527 Page seeded by OCA on Sun May 4 04:17:10 2008

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

OCA

@@ Line 1: / Line 1: @@
 [[Image:2ft7.gif|left|200px]]
- {{Structure
+<!--
-|PDB= 2ft7 |SIZE=350|CAPTION= <scene name='initialview01'>2ft7</scene>, resolution 1.400&Aring;
+The line below this paragraph, containing "STRUCTURE_2ft7", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=CU1:COPPER+(I)+ION'>CU1</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= azu ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=287 Pseudomonas aeruginosa])
+-->
-|DOMAIN=
+{{STRUCTURE_2ft7|  PDB=2ft7  |  SCENE=  }}
-|RELATEDENTRY=[[2ft6|2FT6]], [[2ft8|2FT8]], [[2fta|2FTA]]
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2ft7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ft7 OCA], [http://www.ebi.ac.uk/pdbsum/2ft7 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2ft7 RCSB]</span>
-}}
 '''Structure of Cu(I)azurin at pH 6, with the metal-binding loop sequence "CTFPGHSALM" replaced with "CTPHPM"'''
@@ Line 26: / Line 23: @@
 [[Category: Single protein]]
 [[Category: Banfield, M J.]]
-[[Category: blue copper-binding protein]]
+[[Category: Blue copper-binding protein]]
-[[Category: greek-key beta-barrel]]
+[[Category: Greek-key beta-barrel]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May  4 04:17:10 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 03:07:25 2008''