1n7y: Difference between revisions

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[[Image:1n7y.gif|left|200px]]<br /><applet load="1n7y" size="350" color="white" frame="true" align="right" spinBox="true"
caption="1n7y, resolution 1.96&Aring;" />
'''STREPTAVIDIN MUTANT N23E AT 1.96A'''<br />


==Overview==
==STREPTAVIDIN MUTANT N23E AT 1.96A==
An elaborate hydrogen-bonding network contributes to the tight binding of biotin to streptavidin. The specific energetic contributions of hydrogen bonds to the biotin ureido oxygen have previously been investigated by mapping the equilibrium and activation thermodynamic signatures of N23A, N23E, S27A, Y43A and Y43F site-directed mutants [Klumb et al. (1998), Biochemistry, 37, 7657-7663]. The crystal structures of these variants in the unbound and biotin-bound states provide structural insight into the energetic alterations and are described here. High (1.5-2.2 A) to atomic resolution (1.14 A) structures were obtained and structural models were refined to R values ranging from 0.12 to 0.20. The overall folding of streptavidin as described previously has not changed in any of the mutant structures. Major deviations such as side-chain shifts of residues in the binding site are observed only for the N23A and Y43A mutations. In none of the mutants is a systematic shift of biotin observed when one of the hydrogen-bonding partners to the ureido oxygen of biotin is removed. Recent thermodynamic studies report increases of DeltaDeltaG(o) of 5.0-14.6 kJ mol(-1) for these mutants with respect to the wild-type protein. The decreasing stabilities of the complexes of the mutants are discussed in terms of their structures.
<StructureSection load='1n7y' size='340' side='right'caption='[[1n7y]], [[Resolution|resolution]] 1.96&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1n7y]] is a 4 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=1N7Y OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1N7Y FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.96&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1n7y FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1n7y OCA], [https://pdbe.org/1n7y PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1n7y RCSB], [https://www.ebi.ac.uk/pdbsum/1n7y PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1n7y 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/n7/1n7y_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=1n7y ConSurf].
<div style="clear:both"></div>


==About this Structure==
==See Also==
1N7Y is a [http://en.wikipedia.org/wiki/Single_protein 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=1N7Y OCA].
*[[Avidin 3D structures|Avidin 3D structures]]
 
__TOC__
==Reference==
</StructureSection>
Structural studies of hydrogen bonds in the high-affinity streptavidin-biotin complex: mutations of amino acids interacting with the ureido oxygen of biotin., Le Trong I, Freitag S, Klumb LA, Chu V, Stayton PS, Stenkamp RE, Acta Crystallogr D Biol Crystallogr. 2003 Sep;59(Pt 9):1567-73. Epub 2003, Aug 19. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12925786 12925786]
[[Category: Large Structures]]
[[Category: Single protein]]
[[Category: Streptomyces avidinii]]
[[Category: Streptomyces avidinii]]
[[Category: Chu, V.]]
[[Category: Chu V]]
[[Category: Freitag, S.]]
[[Category: Freitag S]]
[[Category: Klumb, L A.]]
[[Category: Klumb LA]]
[[Category: Stayton, P S.]]
[[Category: Le Trong I]]
[[Category: Stenkamp, R E.]]
[[Category: Stayton PS]]
[[Category: Trong, I Le.]]
[[Category: Stenkamp RE]]
[[Category: homotetramer]]
 
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