View source for 1w23


==Crystal structure of phosphoserine aminotransferase from Bacillus alcalophilus==
<StructureSection load='1w23' size='340' side='right'caption='[[1w23]], [[Resolution|resolution]] 1.08&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1w23]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Alkalihalobacillus_alcalophilus Alkalihalobacillus alcalophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1W23 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1W23 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]] 1.08&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=EPE:4-(2-HYDROXYETHYL)-1-PIPERAZINE+ETHANESULFONIC+ACID'>EPE</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</scene>, <scene name='pdbligand=PGE:TRIETHYLENE+GLYCOL'>PGE</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=1w23 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1w23 OCA], [https://pdbe.org/1w23 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1w23 RCSB], [https://www.ebi.ac.uk/pdbsum/1w23 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1w23 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SERC_ALKAL SERC_ALKAL] Catalyzes the reversible conversion of 3-phosphohydroxypyruvate to phosphoserine and of 3-hydroxy-2-oxo-4-phosphonooxybutanoate to phosphohydroxythreonine.<ref>PMID:14646107</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/w2/1w23_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=1w23 ConSurf].
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== Publication Abstract from PubMed ==
The crystal structure of the vitamin B(6)-dependent enzyme phosphoserine aminotransferase from the obligatory alkaliphile Bacillus alcalophilus has been determined at 1.08 A resolution. The model was refined to an R-factor of 11.7% (R(free) = 13.9%). The enzyme displays a narrow pH optimum of enzymatic activity at pH 9.0. The final structure was compared to the previously reported structure of the mesophilic phosphoserine aminotransferase from Escherichia coli and to that of phosphoserine aminotransferase from a facultative alkaliphile, Bacillus circulans subsp. alkalophilus. All three enzymes are homodimers with each monomer comprising a two-domain architecture. Despite the high structural similarity, the alkaliphilic representatives possess a set of distinctive structural features. Two residues directly interacting with pyridoxal-5'-phosphate are replaced, and an additional hydrogen bond to the O3' atom of the cofactor is present in alkaliphilic phosphoserine aminotransferases. The number of hydrogen bonds and hydrophobic interactions at the dimer interface is increased. Hydrophobic interactions between the two domains in the monomers are enhanced. Moreover, the number of negatively charged amino acid residues increases on the solvent-accessible molecular surface and fewer hydrophobic residues are exposed to the solvent. Further, the total amount of ion pairs and ion networks is significantly reduced in the Bacillus enzymes, while the total number of hydrogen bonds is increased. The mesophilic enzyme from Escherichia coli contains two additional beta-strands in a surface loop with a third beta-strand being shorter in the structure. The identified structural features are proposed to be possible factors implicated in the alkaline adaptation of phosphoserine aminotransferase.

Enzyme adaptation to alkaline pH: atomic resolution (1.08 A) structure of phosphoserine aminotransferase from Bacillus alcalophilus.,Dubnovitsky AP, Kapetaniou EG, Papageorgiou AC Protein Sci. 2005 Jan;14(1):97-110. PMID:15608117<ref>PMID:15608117</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 1w23" style="background-color:#fffaf0;"></div>

==See Also==
*[[Phosphoserine aminotransferase|Phosphoserine aminotransferase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Alkalihalobacillus alcalophilus]]
[[Category: Large Structures]]
[[Category: Dubnovitsky A]]
[[Category: Kapetaniou EG]]
[[Category: Papageorgiou AC]]