View source for 2p44


==Complex of a camelid single-domain vhh antibody fragment with RNASE A at 1.8A resolution: SE5A-mono-1 crystal form with five se-met sites (M34, M51, F68M, M83, L86M) in vhh scaffold==
<StructureSection load='2p44' size='340' side='right'caption='[[2p44]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2p44]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Arabian_camel Arabian camel] and [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2P44 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2P44 FirstGlance]. <br>
</td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Pancreatic_ribonuclease Pancreatic ribonuclease], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.27.5 3.1.27.5] </span></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=2p44 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2p44 OCA], [https://pdbe.org/2p44 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2p44 RCSB], [https://www.ebi.ac.uk/pdbsum/2p44 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2p44 ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/RNAS1_BOVIN RNAS1_BOVIN]] Endonuclease that catalyzes the cleavage of RNA on the 3' side of pyrimidine nucleotides. Acts on single stranded and double stranded RNA.<ref>PMID:7479688</ref>  
== 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/p4/2p44_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=2p44 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
A crystallization chaperone is an auxiliary protein that binds to a target of interest, enhances and modulates crystal packing, and provides high-quality phasing information. We critically evaluated the effectiveness of a camelid single-domain antibody (V(H)H) as a crystallization chaperone. By using a yeast surface display system for V(H)H, we successfully introduced additional Met residues in the core of the V(H)H scaffold. We identified a set of SeMet-labeled V(H)H variants that collectively produced six new crystal forms as the complex with the model antigen, RNase A. The crystals exhibited monoclinic, orthorhombic, triclinic, and tetragonal symmetry and have one or two complexes in the asymmetric unit, some of which diffracted to an atomic resolution. The phasing power of the Met-enriched V(H)H chaperone allowed for auto-building the entire complex using single-anomalous dispersion technique (SAD) without the need for introducing SeMet into the target protein. We show that phases produced by combining SAD and V(H)H model-based phases are accurate enough to easily solve structures of the size reported here, eliminating the need to collect multiple wavelength multiple-anomalous dispersion (MAD) data. Together with the presence of high-throughput selection systems (e.g., phage display libraries) for V(H)H, the enhanced V(H)H domain described here will be an excellent scaffold for producing effective crystallization chaperones.

Toward chaperone-assisted crystallography: protein engineering enhancement of crystal packing and X-ray phasing capabilities of a camelid single-domain antibody (VHH) scaffold.,Tereshko V, Uysal S, Koide A, Margalef K, Koide S, Kossiakoff AA Protein Sci. 2008 Jul;17(7):1175-87. Epub 2008 Apr 29. PMID:18445622<ref>PMID:18445622</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2p44" style="background-color:#fffaf0;"></div>

==See Also==
*[[Antibody 3D structures|Antibody 3D structures]]
*[[Ribonuclease 3D structures|Ribonuclease 3D structures]]
*[[3D structures of non-human antibody|3D structures of non-human antibody]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Arabian camel]]
[[Category: Bos taurus]]
[[Category: Large Structures]]
[[Category: Pancreatic ribonuclease]]
[[Category: Koide, A]]
[[Category: Koide, S]]
[[Category: Kossiakoff, A A]]
[[Category: Margalef, K]]
[[Category: Tereshko, V]]
[[Category: Uysal, S]]
[[Category: Cab-rn05]]
[[Category: Camelid single-domain antibody]]
[[Category: Hydrolase]]
[[Category: Hydrolase-immune system complex]]
[[Category: Rnase some]]
[[Category: Semet phasing]]
[[Category: Vhh]]
[[Category: Yeast surface display]]