View source for 6mag


==native BbvCI B2 dimer in space group C222==
<StructureSection load='6mag' size='340' side='right'caption='[[6mag]], [[Resolution|resolution]] 2.07&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6mag]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Brevibacillus_brevis Brevibacillus brevis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6MAG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6MAG 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]] 2.07&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></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=6mag FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6mag OCA], [https://pdbe.org/6mag PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6mag RCSB], [https://www.ebi.ac.uk/pdbsum/6mag PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6mag ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q5D6Y4_BREBE Q5D6Y4_BREBE] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
BbvCI, a Type IIT restriction endonuclease, recognizes and cleaves the seven base pair sequence 5'-CCTCAGC-3', generating 3-base, 5'-overhangs. BbvCI is composed of two protein subunits, each containing one catalytic site. Either site can be inactivated by mutation resulting in enzyme variants that nick DNA in a strand-specific manner. Here we demonstrate that the holoenzyme is labile, with the R1 subunit dissociating at low pH. Crystallization of the R2 subunit under such conditions revealed an elongated dimer with the two catalytic sites located on opposite sides. Subsequent crystallization at physiological pH revealed a tetramer comprising two copies of each subunit, with a pair of deep clefts each containing two catalytic sites appropriately positioned and oriented for DNA cleavage. This domain organization was further validated with single-chain protein constructs in which the two enzyme subunits were tethered via peptide linkers of variable length. We were unable to crystallize a DNA-bound complex; however, structural similarity to previously crystallized restriction endonucleases facilitated creation of an energy-minimized model bound to DNA, and identification of candidate residues responsible for target recognition. Mutation of residues predicted to recognize the central C:G base pair resulted in an altered enzyme that recognizes and cleaves CCTNAGC (N = any base).

Structure, subunit organization and behavior of the asymmetric Type IIT restriction endonuclease BbvCI.,Shen BW, Doyle L, Bradley P, Heiter DF, Lunnen KD, Wilson GG, Stoddard BL Nucleic Acids Res. 2019 Jan 10;47(1):450-467. doi: 10.1093/nar/gky1059. PMID:30395313<ref>PMID:30395313</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6mag" style="background-color:#fffaf0;"></div>

==See Also==
*[[Endonuclease 3D structures|Endonuclease 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Brevibacillus brevis]]
[[Category: Large Structures]]
[[Category: Shen BW]]
[[Category: Stoddard BL]]