This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.


2rtr

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Current revision (09:23, 21 February 2024) (edit) (undo)
 
(12 intermediate revisions not shown.)
Line 1: Line 1:
-
[[Image:2rtr.gif|left|200px]]
 
-
<!--
+
==STREPTAVIDIN-2-IMINOBIOTIN COMPLEX, PH 4.0, SPACE GROUP I222==
-
The line below this paragraph, containing "STRUCTURE_2rtr", creates the "Structure Box" on the page.
+
<StructureSection load='2rtr' size='340' side='right'caption='[[2rtr]], [[Resolution|resolution]] 1.62&Aring;' scene=''>
-
You may change the PDB parameter (which sets the PDB file loaded into the applet)
+
== Structural highlights ==
-
or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
+
<table><tr><td colspan='2'>[[2rtr]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_avidinii Streptomyces avidinii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2RTR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2RTR FirstGlance]. <br>
-
or leave the SCENE parameter empty for the default display.
+
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.62&#8491;</td></tr>
-
-->
+
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IMI:2-IMINOBIOTIN'>IMI</scene></td></tr>
-
{{STRUCTURE_2rtr| PDB=2rtr | SCENE= }}
+
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2rtr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2rtr OCA], [https://pdbe.org/2rtr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2rtr RCSB], [https://www.ebi.ac.uk/pdbsum/2rtr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2rtr ProSAT]</span></td></tr>
 +
</table>
 +
== Function ==
 +
[https://www.uniprot.org/uniprot/SAV_STRAV SAV_STRAV] The biological function of streptavidin is not known. Forms a strong non-covalent specific complex with biotin (one molecule of biotin per subunit of streptavidin).
 +
== Evolutionary Conservation ==
 +
[[Image:Consurf_key_small.gif|200px|right]]
 +
Check<jmol>
 +
<jmolCheckbox>
 +
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/rt/2rtr_consurf.spt"</scriptWhenChecked>
 +
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
 +
<text>to colour the structure by Evolutionary Conservation</text>
 +
</jmolCheckbox>
 +
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2rtr ConSurf].
 +
<div style="clear:both"></div>
-
'''STREPTAVIDIN-2-IMINOBIOTIN COMPLEX, PH 4.0, SPACE GROUP I222'''
+
==See Also==
-
 
+
*[[Avidin 3D structures|Avidin 3D structures]]
-
 
+
__TOC__
-
==Overview==
+
</StructureSection>
-
The remarkable stability of the streptavidin tetramer towards subunit dissociation becomes even greater upon binding of biotin. At two equivalent extensive monomer-monomer interfaces, monomers tightly associate into dimers that in turn associate into the tetramer at a less extensive dimer-dimer interface. To probe the structural basis for the enhancement of the stability of streptavidin by biotin, the crystal structures of apostreptavidin and its complexes with biotin and other small molecule and cyclic peptide ligands were determined and compared at resolutions as high as 1.36 A over a range of pH values from as low as 1.39. At low pH dramatic changes occur in the conformation and intersubunit hydrogen bonds involving the loop comprising Asp61 to Ser69. The hydrogen-bonded salt bridge between Asp61 Odelta2 and His87 Ndelta1, observed at higher pH, is replaced with a strong hydrogen bond between Asp61 Odelta1 and Asn85 Odelta1. Through crystallography at multiple pH values, the pH where this conformational change occurs, and thus the pKa of Asp61, was determined in crystals of space group I222 and/or I4122 of apostreptavidin and complexes. A range in pKa values for Asp61 was observed in these structures, the lowest being 1.78+/-0.19 for I222 streptavidin-biotin in 2.9 M (NH4)2SO4. At low pH the decrease in pKa of Asp61 and preservation of the intersubunit Asp61 Odelta2-Ndelta1 His87 hydrogen-bonded salt bridge in streptavidin-biotin versus apostreptavidin or streptavidin-peptide complexes is associated with an ordering of the flexible flap comprising residues Ala46 to Glu51, that in turn orders the Arg84 side-chain of a neighboring loop through resulting hydrogen bonds. Ordering of Arg84 in close proximity to the strong intersubunit interface appears to stabilize the conformation associated with the Asp61 Odelta2-Ndelta1 His87 hydrogen-bonded salt bridge. Thus, in addition to the established role of biotin in tetramer stabilization by direct mediation of intersubunit interactions at the weak interface through contact with Trp120, biotin may enhance tetramer stability at the strong interface more indirectly by ordering loop residues.
+
[[Category: Large Structures]]
-
 
+
-
==About this Structure==
+
-
2RTR is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_avidinii Streptomyces avidinii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2RTR OCA].
+
-
 
+
-
==Reference==
+
-
Binding of biotin to streptavidin stabilizes intersubunit salt bridges between Asp61 and His87 at low pH., Katz BA, J Mol Biol. 1997 Dec 19;274(5):776-800. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9405158 9405158]
+
-
[[Category: Single protein]]
+
[[Category: Streptomyces avidinii]]
[[Category: Streptomyces avidinii]]
-
[[Category: Katz, B A.]]
+
[[Category: Katz BA]]
-
[[Category: Biotin-binding protein]]
+
-
[[Category: Ph 4 0]]
+
-
[[Category: Streptavidin-2-iminobiotin]]
+
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 17:16:50 2008''
+

Current revision

STREPTAVIDIN-2-IMINOBIOTIN COMPLEX, PH 4.0, SPACE GROUP I222

PDB ID 2rtr

Drag the structure with the mouse to rotate

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2rtr"
Personal tools