View source for 5ohx


==Structure of active cystathionine B-synthase from Apis mellifera==
<StructureSection load='5ohx' size='340' side='right'caption='[[5ohx]], [[Resolution|resolution]] 3.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ohx]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Apis_mellifera Apis mellifera]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5OHX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5OHX 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]] 3.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5-PHOSPHATE'>PLP</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=5ohx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ohx OCA], [https://pdbe.org/5ohx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ohx RCSB], [https://www.ebi.ac.uk/pdbsum/5ohx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ohx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CBS_APIME CBS_APIME] Hydro-lyase catalyzing the first step of the transsulfuration pathway, where the hydroxyl group of L-serine is displaced by L-homocysteine in a beta-replacement reaction to form L-cystathionine, the precursor of L-cysteine.<ref>PMID:29275181</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Cystathionine beta-synthase (CBS), the key enzyme in the transsulfuration pathway, links methionine metabolism to the biosynthesis of cellular redox controlling molecules. CBS catalyzes the pyridoxal-5'-phosphate-dependent condensation of serine and homocysteine to form cystathionine, which is subsequently converted into cysteine. Besides maintaining cellular sulfur amino acid homeostasis, CBS also catalyzes multiple hydrogen sulfide-generating reactions using cysteine and homocysteine as substrates. In mammals, CBS is activated by S-adenosylmethionine (AdoMet), where it can adopt two different conformations (basal and activated), but exists as a unique highly active species in fruit fly Drosophila melanogaster. Here we present the crystal structure of CBS from honeybey Apis mellifera, which shows a constitutively active dimeric species and let explain why the enzyme is not allosterically regulated by AdoMet. In addition, comparison of available CBS structures unveils a substrate-induced closure of the catalytic cavity, which in humans is affected by the AdoMet-dependent regulation and likely impaired by the homocystinuria causing mutation T191M.

Crystal structure of cystathionine beta-synthase from honeybee Apis mellifera.,Gimenez-Mascarell P, Majtan T, Oyenarte I, Ereno-Orbea J, Majtan J, Klaudiny J, Kraus JP, Martinez-Cruz LA J Struct Biol. 2017 Dec 21. pii: S1047-8477(17)30231-9. doi:, 10.1016/j.jsb.2017.12.008. PMID:29275181<ref>PMID:29275181</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5ohx" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cystathionine ÃÂ²-synthase 3D structures|Cystathionine ÃÂ²-synthase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Apis mellifera]]
[[Category: Large Structures]]
[[Category: Ereno-Orbea J]]
[[Category: Gimenez-Mascarell P]]
[[Category: Klaudiny J]]
[[Category: Kraus JP]]
[[Category: Majtan J]]
[[Category: Majtan T]]
[[Category: Martinez-Cruz LA]]
[[Category: Oyenarte I]]