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4i14

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Revision as of 06:50, 5 August 2016

Crystal Structure of Mtb-ribA2 (Rv1415)

Structural highlights

4i14 is a 2 chain structure with sequence from Mycta. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	,
Related:	3mio
Gene:	MRA_1424, ribBA, Rv1415 (MYCTA)
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[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).

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^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Singh M, Kumar P, Yadav S, Gautam R, Sharma N, Karthikeyan S. The crystal structure reveals the molecular mechanism of bifunctional 3,4-dihydroxy-2-butanone 4-phosphate synthase/GTP cyclohydrolase II (Rv1415) from Mycobacterium tuberculosis. Acta Crystallogr D Biol Crystallogr. 2013 Sep;69(Pt 9):1633-44. doi:, 10.1107/S0907444913011402. Epub 2013 Aug 15. PMID:23999287 doi:http://dx.doi.org/10.1107/S0907444913011402

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4i14"

@@ Line 1: / Line 1: @@
 ==Crystal Structure of Mtb-ribA2 (Rv1415)==
 <StructureSection load='4i14' size='340' side='right' caption='[[4i14]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
@@ Line 6: / Line 7: @@
 <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>
+<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://pdbe.org/4i14 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4i14 RCSB], [http://www.ebi.ac.uk/pdbsum/4i14 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4i14 ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 18: / Line 19: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 4i14" style="background-color:#fffaf0;"></div>
 == References ==
 <references/>

4i14

From Proteopedia

Revision as of 06:50, 5 August 2016

Crystal Structure of Mtb-ribA2 (Rv1415)

Structural highlights

Function

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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