2b4q
From Proteopedia
(New page: 200px<br /><applet load="2b4q" size="450" color="white" frame="true" align="right" spinBox="true" caption="2b4q, resolution 2.30Å" /> '''Pseudomonas aerugino...) |
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| - | [[Image:2b4q.gif|left|200px]]<br /><applet load="2b4q" size=" | + | [[Image:2b4q.gif|left|200px]]<br /><applet load="2b4q" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2b4q, resolution 2.30Å" /> | caption="2b4q, resolution 2.30Å" /> | ||
'''Pseudomonas aeruginosa RhlG/NADP active-site complex'''<br /> | '''Pseudomonas aeruginosa RhlG/NADP active-site complex'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Rhamnolipids are extracellular biosurfactants and virulence factors | + | Rhamnolipids are extracellular biosurfactants and virulence factors secreted by the opportunistic human pathogen Pseudomonas aeruginosa that are required for swarming motility. The rhlG gene is essential for rhamnolipid formation, and the RhlG enzyme is thought to divert fatty acid synthesis intermediates into the rhamnolipid biosynthetic pathway based on its similarity to FabG, the beta-ketoacyl-acyl carrier protein (ACP) reductase of type II fatty acid synthesis. Crystallographic analysis reveals that the overall structures of the RhlG.NADP+ and FabG.NADP+ complexes are indeed similar, but there are key differences related to function. RhlG does not undergo the conformational changes upon NADP(H) binding at the active site that in FabG are the structural basis of negative allostery. Also, the acyl chain-binding pocket of RhlG is narrow and rigid compared with the larger, flexible substrate-binding subdomain in FabG. Finally, RhlG lacks a positively charged/hydrophobic surface feature adjacent to the active site that is found on enzymes like FabG that recognize the ACP of fatty acid synthesis. RhlG catalyzed the NADPH-dependent reduction of beta-ketodecanoyl-ACP to beta-d-hydroxydecanoyl-ACP. However, the enzyme was 2000-fold less active than FabG in carrying out the same reaction. These structural and biochemical studies establish RhlG as a NADPH-dependent beta-ketoacyl reductase of the SDR protein superfamily and further suggest that the ACP of fatty acid synthesis does not carry the substrates for RhlG. |
==About this Structure== | ==About this Structure== | ||
| - | 2B4Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa] with NAP as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/3-oxoacyl-[acyl-carrier-protein]_reductase 3-oxoacyl-[acyl-carrier-protein] reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.100 1.1.1.100] Full crystallographic information is available from [http:// | + | 2B4Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa] with <scene name='pdbligand=NAP:'>NAP</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/3-oxoacyl-[acyl-carrier-protein]_reductase 3-oxoacyl-[acyl-carrier-protein] reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.100 1.1.1.100] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2B4Q OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Pseudomonas aeruginosa]] | [[Category: Pseudomonas aeruginosa]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Miller, D | + | [[Category: Miller, D J.]] |
| - | [[Category: White, S | + | [[Category: White, S W.]] |
[[Category: NAP]] | [[Category: NAP]] | ||
[[Category: pseudomonas aeruginosa]] | [[Category: pseudomonas aeruginosa]] | ||
[[Category: rhlg-nadp complex]] | [[Category: rhlg-nadp complex]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:34:08 2008'' |
Revision as of 14:34, 21 February 2008
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Pseudomonas aeruginosa RhlG/NADP active-site complex
Overview
Rhamnolipids are extracellular biosurfactants and virulence factors secreted by the opportunistic human pathogen Pseudomonas aeruginosa that are required for swarming motility. The rhlG gene is essential for rhamnolipid formation, and the RhlG enzyme is thought to divert fatty acid synthesis intermediates into the rhamnolipid biosynthetic pathway based on its similarity to FabG, the beta-ketoacyl-acyl carrier protein (ACP) reductase of type II fatty acid synthesis. Crystallographic analysis reveals that the overall structures of the RhlG.NADP+ and FabG.NADP+ complexes are indeed similar, but there are key differences related to function. RhlG does not undergo the conformational changes upon NADP(H) binding at the active site that in FabG are the structural basis of negative allostery. Also, the acyl chain-binding pocket of RhlG is narrow and rigid compared with the larger, flexible substrate-binding subdomain in FabG. Finally, RhlG lacks a positively charged/hydrophobic surface feature adjacent to the active site that is found on enzymes like FabG that recognize the ACP of fatty acid synthesis. RhlG catalyzed the NADPH-dependent reduction of beta-ketodecanoyl-ACP to beta-d-hydroxydecanoyl-ACP. However, the enzyme was 2000-fold less active than FabG in carrying out the same reaction. These structural and biochemical studies establish RhlG as a NADPH-dependent beta-ketoacyl reductase of the SDR protein superfamily and further suggest that the ACP of fatty acid synthesis does not carry the substrates for RhlG.
About this Structure
2B4Q is a Single protein structure of sequence from Pseudomonas aeruginosa with as ligand. Active as [acyl-carrier-protein_reductase 3-oxoacyl-[acyl-carrier-protein] reductase], with EC number 1.1.1.100 Full crystallographic information is available from OCA.
Reference
Structure of RhlG, an essential beta-ketoacyl reductase in the rhamnolipid biosynthetic pathway of Pseudomonas aeruginosa., Miller DJ, Zhang YM, Rock CO, White SW, J Biol Chem. 2006 Jun 30;281(26):18025-32. Epub 2006 Apr 18. PMID:16624803 [[Category: 3-oxoacyl-[acyl-carrier-protein] reductase]]
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