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| | <StructureSection load='6a35' size='340' side='right'caption='[[6a35]], [[Resolution|resolution]] 2.65Å' scene=''> | | <StructureSection load='6a35' size='340' side='right'caption='[[6a35]], [[Resolution|resolution]] 2.65Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6a35]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6A35 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6A35 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6a35]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Pyrococcus_horikoshii_OT3 Pyrococcus horikoshii OT3]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6A35 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6A35 FirstGlance]. <br> |
| - | </td></tr><tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">PH0702 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=70601 Pyrococcus horikoshii])</td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.65Å</td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/S-methyl-5-thioribose-1-phosphate_isomerase S-methyl-5-thioribose-1-phosphate isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.1.23 5.3.1.23] </span></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=6a35 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6a35 OCA], [https://pdbe.org/6a35 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6a35 RCSB], [https://www.ebi.ac.uk/pdbsum/6a35 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6a35 ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6a35 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6a35 OCA], [http://pdbe.org/6a35 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6a35 RCSB], [http://www.ebi.ac.uk/pdbsum/6a35 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6a35 ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/MTNA_PYRHO MTNA_PYRHO]] Catalyzes the interconversion of methylthioribose-1-phosphate (MTR-1-P) into methylthioribulose-1-phosphate (MTRu-1-P).[HAMAP-Rule:MF_01678] | + | [https://www.uniprot.org/uniprot/MTNA_PYRHO MTNA_PYRHO] Catalyzes the interconversion of methylthioribose-1-phosphate (MTR-1-P) into methylthioribulose-1-phosphate (MTRu-1-P).[HAMAP-Rule:MF_01678] |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </StructureSection> | | </StructureSection> |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Pyrococcus horikoshii]] | + | [[Category: Pyrococcus horikoshii OT3]] |
| - | [[Category: S-methyl-5-thioribose-1-phosphate isomerase]]
| + | [[Category: Gogoi P]] |
| - | [[Category: Gogoi, P]] | + | [[Category: Kanaujia SP]] |
| - | [[Category: Kanaujia, S P]] | + | [[Category: Mordina P]] |
| - | [[Category: Mordina, P]] | + | |
| - | [[Category: Cis-phosphoenolate intermediate]]
| + | |
| - | [[Category: Hydride transfer]]
| + | |
| - | [[Category: Isomerase]]
| + | |
| - | [[Category: Methionine salvage pathway]]
| + | |
| - | [[Category: Ph0702]]
| + | |
| Structural highlights
Function
MTNA_PYRHO Catalyzes the interconversion of methylthioribose-1-phosphate (MTR-1-P) into methylthioribulose-1-phosphate (MTRu-1-P).[HAMAP-Rule:MF_01678]
Publication Abstract from PubMed
5-Methylthioribose 1-phosphate isomerase (M1Pi) is a crucial enzyme involved in the universally conserved methionine salvage pathway (MSP) where it is known to catalyze the conversion of 5-methylthioribose 1-phosphate (MTR-1-P) to 5-methylthioribulose 1-phosphate (MTRu-1-P) via a mechanism which remains unspecified till date. Furthermore, although M1Pi has a discrete function, it surprisingly shares high structural similarity with two functionally non-related proteins such as ribose-1,5-bisphosphate isomerase (R15Pi) and the regulatory subunits of eukaryotic translation initiation factor 2B (eIF2B). To identify the distinct structural features that lead to divergent functional obligations of M1Pi as well as to understand the mechanism of enzyme catalysis, the crystal structure of M1Pi from a hyperthermophilic archaeon Pyrococcus horikoshii OT3 was determined. A meticulous structural investigation of the dimeric M1Pi revealed the presence of an N-terminal extension and a hydrophobic patch absent in R15Pi and the regulatory alpha-subunit of eIF2B. Furthermore, unlike R15Pi in which a kink formation is observed in one of the helices, the domain movement of M1Pi is distinguished by a forward shift in a loop covering the active-site pocket. All these structural attributes contribute towards a hydrophobic microenvironment in the vicinity of the active site of the enzyme making it favorable for the reaction mechanism to commence. Thus, a hydrophobic active-site microenvironment in addition to the availability of optimal amino-acid residues surrounding the catalytic residues in M1Pi led us to propose its probable reaction mechanism via a cis-phosphoenolate intermediate formation.
Structural insights into the catalytic mechanism of 5-methylthioribose 1-phosphate isomerase.,Gogoi P, Mordina P, Kanaujia SP J Struct Biol. 2018 Nov 22. pii: S1047-8477(18)30290-9. doi:, 10.1016/j.jsb.2018.11.007. PMID:30471343[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Gogoi P, Mordina P, Kanaujia SP. Structural insights into the catalytic mechanism of 5-methylthioribose 1-phosphate isomerase. J Struct Biol. 2018 Nov 22. pii: S1047-8477(18)30290-9. doi:, 10.1016/j.jsb.2018.11.007. PMID:30471343 doi:http://dx.doi.org/10.1016/j.jsb.2018.11.007
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