1xn1
From Proteopedia
(New page: 200px<br /><applet load="1xn1" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xn1, resolution 3.05Å" /> '''Crystal Structure Of...) |
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| - | [[Image:1xn1.gif|left|200px]]<br /><applet load="1xn1" size=" | + | [[Image:1xn1.gif|left|200px]]<br /><applet load="1xn1" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1xn1, resolution 3.05Å" /> | caption="1xn1, resolution 3.05Å" /> | ||
'''Crystal Structure Of Lumazine Synthase From Brucella Abortus (Orthorhombic Form At 3.05 Angstroms)'''<br /> | '''Crystal Structure Of Lumazine Synthase From Brucella Abortus (Orthorhombic Form At 3.05 Angstroms)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The enzyme lumazine synthase (LS) catalyzes the penultimate step of | + | The enzyme lumazine synthase (LS) catalyzes the penultimate step of riboflavin biosynthesis in plants, fungi and bacteria. The quaternary structure of the polypeptide differs between species, existing as pentamers or as icosahedrally arranged dodecamers of pentamers with 60 subunits. The pathogen Brucella spp. expresses two proteins that exhibit LS activity, RibH1 and RibH2. The latter enzyme belongs to a novel third category of quaternary arrangement for LS, that of a decameric structure assembled as a head-to-head oriented dimer of pentamers. In contrast, the RibH1 enzyme is assembled as a pentamer, as noted for several other LS enzymes. RibH1 appears to be the functional LS in Brucella spp., whereas RibH2, an enzyme of lower catalytic activity, is a virulence factor presumably acting in response to oxidative stress. The latter observation prompted us to further investigate the structural and catalytic properties of RibH2 in order to clarify the biological function of this enzyme. Here, we present a detailed analysis of two new crystallographic forms of RibH2 that explain the low catalytic activity of this enzyme in comparison with RibH1 and other LSs. Additionally, we analyze the effect of pH on the structure of this enzyme, and the binding of riboflavin and 6,7-dimethyl-8-ribityllumazine to its active site. |
==About this Structure== | ==About this Structure== | ||
| - | 1XN1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Brucella_abortus Brucella abortus] with PO4, SO4 and NA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Riboflavin_synthase Riboflavin synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.9 2.5.1.9] Full crystallographic information is available from [http:// | + | 1XN1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Brucella_abortus Brucella abortus] with <scene name='pdbligand=PO4:'>PO4</scene>, <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=NA:'>NA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Riboflavin_synthase Riboflavin synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.9 2.5.1.9] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XN1 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Riboflavin synthase]] | [[Category: Riboflavin synthase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Braden, B | + | [[Category: Braden, B C.]] |
| - | [[Category: Goldbaum, F | + | [[Category: Goldbaum, F A.]] |
| - | [[Category: Guimaraes, B | + | [[Category: Guimaraes, B G.]] |
[[Category: Klinke, S.]] | [[Category: Klinke, S.]] | ||
| - | [[Category: Vega, D | + | [[Category: Vega, D R.]] |
[[Category: Zylberman, V.]] | [[Category: Zylberman, V.]] | ||
[[Category: NA]] | [[Category: NA]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:56:36 2008'' |
Revision as of 13:56, 21 February 2008
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Crystal Structure Of Lumazine Synthase From Brucella Abortus (Orthorhombic Form At 3.05 Angstroms)
Overview
The enzyme lumazine synthase (LS) catalyzes the penultimate step of riboflavin biosynthesis in plants, fungi and bacteria. The quaternary structure of the polypeptide differs between species, existing as pentamers or as icosahedrally arranged dodecamers of pentamers with 60 subunits. The pathogen Brucella spp. expresses two proteins that exhibit LS activity, RibH1 and RibH2. The latter enzyme belongs to a novel third category of quaternary arrangement for LS, that of a decameric structure assembled as a head-to-head oriented dimer of pentamers. In contrast, the RibH1 enzyme is assembled as a pentamer, as noted for several other LS enzymes. RibH1 appears to be the functional LS in Brucella spp., whereas RibH2, an enzyme of lower catalytic activity, is a virulence factor presumably acting in response to oxidative stress. The latter observation prompted us to further investigate the structural and catalytic properties of RibH2 in order to clarify the biological function of this enzyme. Here, we present a detailed analysis of two new crystallographic forms of RibH2 that explain the low catalytic activity of this enzyme in comparison with RibH1 and other LSs. Additionally, we analyze the effect of pH on the structure of this enzyme, and the binding of riboflavin and 6,7-dimethyl-8-ribityllumazine to its active site.
About this Structure
1XN1 is a Single protein structure of sequence from Brucella abortus with , and as ligands. Active as Riboflavin synthase, with EC number 2.5.1.9 Full crystallographic information is available from OCA.
Reference
Crystallographic studies on decameric Brucella spp. Lumazine synthase: a novel quaternary arrangement evolved for a new function?, Klinke S, Zylberman V, Vega DR, Guimaraes BG, Braden BC, Goldbaum FA, J Mol Biol. 2005 Oct 14;353(1):124-37. PMID:16165152
Page seeded by OCA on Thu Feb 21 15:56:36 2008
Categories: Brucella abortus | Riboflavin synthase | Single protein | Braden, B C. | Goldbaum, F A. | Guimaraes, B G. | Klinke, S. | Vega, D R. | Zylberman, V. | NA | PO4 | SO4 | Transferase
