View source for 6ahi


==Crystal structure of O-acetylserine dependent cystathionine beta-synthase from Helicobacter pylori.==
<StructureSection load='6ahi' size='340' side='right'caption='[[6ahi]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6ahi]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Helicobacter_pylori_26695 Helicobacter pylori 26695]. This structure supersedes the now removed PDB entries [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=5hbg 5hbg], [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=4r2v 4r2v] and [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=4i1x 4i1x]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6AHI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6AHI 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=LLP:(2S)-2-AMINO-6-[[3-HYDROXY-2-METHYL-5-(PHOSPHONOOXYMETHYL)PYRIDIN-4-YL]METHYLIDENEAMINO]HEXANOIC+ACID'>LLP</scene>, <scene name='pdbligand=MET:METHIONINE'>MET</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=6ahi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6ahi OCA], [https://pdbe.org/6ahi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6ahi RCSB], [https://www.ebi.ac.uk/pdbsum/6ahi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6ahi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CYSM_HELPY CYSM_HELPY] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
O-acetylserine sulfhydrylase (OASS) and cystathionine beta-synthase (CBS) are members of the PLP-II family, and involved in L-cysteine production. OASS produces L-cysteine via a de novo pathway while CBS participates in the reverse transsulfuration pathway. O-acetylserine-dependent CBS (OCBS) was previously identified as a new member of the PLP-II family, which are predominantly seen in bacteria. The bacterium Helicobacter pylori possess only one OASS (hp0107) gene and we showed that the protein coded by this gene actually functions as an OCBS and utilizes L-homocysteine and O-acetylserine (OAS) to produce cystathionine. HpOCBS did not show CBS activity with the substrate L-serine and required OAS exclusively. The HpOCBS structure in complex with methionine showed a closed cleft state, explaining the initial mode of substrate binding. Sequence and structural analyses showed differences between the active sites of OCBS and CBS, and explain their different substrate preferences. We identified three hydrophobic residues near the active site of OCBS, corresponding to one serine and two tyrosine residues in CBSs. Mutational studies were performed on HpOCBS and Saccharomyces cerevisiae CBS. A ScCBS double mutant (Y158F/Y226V) did not display activity with L-serine, indicating indispensability of these polar residues for selecting substrate L-serine, however, did show activity with OAS.

Identification and characterization of Helicobacter pylori O-acetylserine-dependent cystathionine beta-synthase, a distinct member of the PLP-II family.,Devi S, Tarique KF, Ali MF, Abdul Rehman SA, Gourinath S Mol Microbiol. 2019 Aug;112(2):718-739. doi: 10.1111/mmi.14315. Epub 2019 Jun 21. PMID:31132312<ref>PMID:31132312</ref>

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

==See Also==
*[[Cystathionine ÃÂ²-synthase 3D structures|Cystathionine ÃÂ²-synthase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Helicobacter pylori 26695]]
[[Category: Large Structures]]
[[Category: Devi S]]
[[Category: Rehman SAA]]
[[Category: Tarique FK]]