View source for 6v82


==Crystal structure of tryptophan synthase from Chlamydia trachomatis D/UW-3/CX==
<StructureSection load='6v82' size='340' side='right'caption='[[6v82]], [[Resolution|resolution]] 2.42&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6v82]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Chlamydia_trachomatis_D/UW-3/CX Chlamydia trachomatis D/UW-3/CX]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6V82 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6V82 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]] 2.424&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FRU:FRUCTOSE'>FRU</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <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=PRD_900003:sucrose'>PRD_900003</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=6v82 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6v82 OCA], [https://pdbe.org/6v82 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6v82 RCSB], [https://www.ebi.ac.uk/pdbsum/6v82 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6v82 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TRPA_CHLTR TRPA_CHLTR] The alpha subunit is responsible for the aldol cleavage of indoleglycerol phosphate to indole and glyceraldehyde 3-phosphate.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Intracellular growth and pathogenesis of Chlamydia species is controlled by the availability of tryptophan, yet the complete biosynthetic pathway for l-Trp is absent among members of the genus. Some representatives, however, preserve genes encoding tryptophan synthase, TrpAB - a bifunctional enzyme catalyzing the last two steps in l-Trp synthesis. TrpA (subunit alpha) converts indole-3-glycerol phosphate into indole and glyceraldehyde-3-phosphate (alpha reaction). The former compound is subsequently used by TrpB (subunit beta) to produce l-Trp in the presence of l-Ser and a pyridoxal 5'-phosphate cofactor (beta reaction). Previous studies have indicated that in Chlamydia, TrpA has lost its catalytic activity yet remains associated with TrpB to support the beta reaction. Here, we provide detailed analysis of the TrpAB from C. trachomatis D/UW-3/CX, confirming that accumulation of mutations in the active site of TrpA renders it enzymatically inactive, despite the conservation of the catalytic residues. We also show that TrpA remains a functional component of the TrpAB complex, increasing the activity of TrpB by four-fold. The side chain of non-conserved betaArg267 functions as cation effector, potentially rendering the enzyme less susceptible to the solvent ion composition. The observed structural and functional changes detected herein were placed in a broader evolutionary and genomic context, allowing identification of these mutations in relation to their trp gene contexts in which they occur. Moreover, in agreement with the in vitro data, partial relaxation of purifying selection for TrpA, but not for TrpB, was detected, reinforcing a partial loss of TrpA functions during the course of evolution.

Catalytically impaired TrpA subunit of tryptophan synthase from Chlamydia trachomatis is an allosteric regulator of TrpB.,Michalska K, Wellington S, Maltseva N, Jedrzejczak R, Selem-Mojica N, Rosas-Becerra LR, Barona-Gomez F, Hung DT, Joachimiak A Protein Sci. 2021 Sep;30(9):1904-1918. doi: 10.1002/pro.4143. Epub 2021 Jun 16. PMID:34107106<ref>PMID:34107106</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6v82" style="background-color:#fffaf0;"></div>

==See Also==
*[[Tryptophan synthase 3D structures|Tryptophan synthase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Chlamydia trachomatis D/UW-3/CX]]
[[Category: Large Structures]]
[[Category: Jedrzejczak R]]
[[Category: Joachimiak A]]
[[Category: Maltseva N]]
[[Category: Michalska K]]