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4i14
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| - | + | ==Crystal Structure of Mtb-ribA2 (Rv1415)== | |
| - | + | <StructureSection load='4i14' size='340' side='right' caption='[[4i14]], [[Resolution|resolution]] 3.00Å' scene=''> | |
| - | + | == Structural highlights == | |
| - | + | <table><tr><td colspan='2'>[[4i14]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Mycta Mycta]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4I14 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4I14 FirstGlance]. <br> | |
| - | ==Function== | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> |
| + | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3mio|3mio]]</td></tr> | ||
| + | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">MRA_1424, ribBA, Rv1415 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=419947 MYCTA])</td></tr> | ||
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4i14 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4i14 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4i14 RCSB], [http://www.ebi.ac.uk/pdbsum/4i14 PDBsum]</span></td></tr> | ||
| + | </table> | ||
| + | == Function == | ||
[[http://www.uniprot.org/uniprot/RIBBA_MYCTA RIBBA_MYCTA]] Catalyzes the conversion of D-ribulose 5-phosphate to formate and 3,4-dihydroxy-2-butanone 4-phosphate (By similarity). Catalyzes the conversion of GTP to 2,5-diamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate (DARP), formate and pyrophosphate (By similarity). | [[http://www.uniprot.org/uniprot/RIBBA_MYCTA RIBBA_MYCTA]] Catalyzes the conversion of D-ribulose 5-phosphate to formate and 3,4-dihydroxy-2-butanone 4-phosphate (By similarity). Catalyzes the conversion of GTP to 2,5-diamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate (DARP), formate and pyrophosphate (By similarity). | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | The enzymes 3,4-dihydroxy-2-butanone 4-phosphate synthase (DHBPS) and GTP cyclohydrolase II (GCHII) catalyze the initial steps of both branches of the bacterial riboflavin-biosynthesis pathway. The structures and molecular mechanisms of DHBPS and GCHII as separate polypeptides are known; however, their organization and molecular mechanism as a bifunctional enzyme are unknown to date. Here, the crystal structure of an essential bifunctional DHBPS/GCHII enzyme from Mycobacterium tuberculosis (Mtb-ribA2) is reported at 3.0 A resolution. The crystal structure revealed two conformationally different molecules of Mtb-ribA2 in the asymmetric unit that form a dimer via their GCHII domains. Interestingly, analysis of the crystal packing revealed a long `helical-like oligomer' formed by DHBPS and GCHII functional homodimers, thus generating an `open-ended' unit-cell lattice. However, size-exclusion chromatography studies suggest that Mtb-ribA2 exists as a dimer in solution. To understand the discrepancy between the oligomerization observed in solution and in the crystal structure, the DHBPS (Mtb-DHBPS) and GCHII (Mtb-GCHII) domains of Mtb-ribA2 have been cloned, expressed and purified as His-tagged proteins. Size-exclusion chromatography studies indicated that Mtb-GCHII is a dimer while Mtb-DHBPS exists as a monomer in solution. Moreover, kinetic studies revealed that the GCHII activities of Mtb-ribA2 and Mtb-GCHII are similar, while the DHBPS activity of Mtb-ribA2 is much higher than that of Mtb-DHBPS alone. Taken together, the results strongly suggest that Mtb-ribA2 exists as a dimer formed through its GCHII domains and requires full-length Mtb-ribA2 for optimal DHBPS activity. | ||
| - | + | The crystal structure reveals the molecular mechanism of bifunctional 3,4-dihydroxy-2-butanone 4-phosphate synthase/GTP cyclohydrolase II (Rv1415) from Mycobacterium tuberculosis.,Singh M, Kumar P, Yadav S, Gautam R, Sharma N, Karthikeyan S Acta Crystallogr D Biol Crystallogr. 2013 Sep;69(Pt 9):1633-44. doi:, 10.1107/S0907444913011402. Epub 2013 Aug 15. PMID:23999287<ref>PMID:23999287</ref> | |
| - | + | ||
| - | == | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| - | + | </div> | |
| + | == References == | ||
| + | <references/> | ||
| + | __TOC__ | ||
| + | </StructureSection> | ||
[[Category: Mycta]] | [[Category: Mycta]] | ||
| - | [[Category: Gautam, R | + | [[Category: Gautam, R]] |
| - | [[Category: Karthikeyan, S | + | [[Category: Karthikeyan, S]] |
| - | [[Category: Kumar, P | + | [[Category: Kumar, P]] |
| - | [[Category: Sharma, N | + | [[Category: Sharma, N]] |
| - | [[Category: Singh, M | + | [[Category: Singh, M]] |
| - | [[Category: Yadav, S | + | [[Category: Yadav, S]] |
[[Category: Antimicrobial]] | [[Category: Antimicrobial]] | ||
[[Category: Dhbp]] | [[Category: Dhbp]] | ||
Revision as of 16:39, 25 December 2014
Crystal Structure of Mtb-ribA2 (Rv1415)
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Categories: Mycta | Gautam, R | Karthikeyan, S | Kumar, P | Sharma, N | Singh, M | Yadav, S | Antimicrobial | Dhbp | Gchii | Gtp | Hydrolase | Lyase | Riba2 | Riboflavin
