PDBsum entry 2b4q

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Oxidoreductase PDB id
Protein chains
256 a.a. *
Waters ×180
* Residue conservation analysis
PDB id:
Name: Oxidoreductase
Title: Pseudomonas aeruginosa rhlg/NADP active-site complex
Structure: Rhamnolipids biosynthesis 3-oxoacyl-[acyl- carrier-protein] reductase. Chain: a, b. Synonym: 3-ketoacyl-acyl carrier protein reductase. Engineered: yes
Source: Pseudomonas aeruginosa. Organism_taxid: 287. Gene: rhlg. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
Biol. unit: Tetramer (from PQS)
2.30Å     R-factor:   0.214     R-free:   0.264
Authors: D.J.Miller,S.W.White
Key ref:
D.J.Miller et al. (2006). Structure of RhlG, an essential beta-ketoacyl reductase in the rhamnolipid biosynthetic pathway of Pseudomonas aeruginosa. J Biol Chem, 281, 18025-18032. PubMed id: 16624803 DOI: 10.1074/jbc.M601687200
26-Sep-05     Release date:   02-May-06    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
Q9RPT1  (RHLG_PSEAE) -  Rhamnolipids biosynthesis 3-oxoacyl-[acyl-carrier-protein] reductase
256 a.a.
256 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class: E.C.  - 3-oxoacyl-[acyl-carrier-protein] reductase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: (3R)-3-hydroxyacyl-[acyl-carrier-protein] + NADP+ = 3-oxoacyl-[acyl- carrier-protein] + NADPH
Bound ligand (Het Group name = NAP)
corresponds exactly
= 3-oxoacyl-[acyl- carrier-protein]
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     metabolic process   2 terms 
  Biochemical function     oxidoreductase activity     2 terms  


DOI no: 10.1074/jbc.M601687200 J Biol Chem 281:18025-18032 (2006)
PubMed id: 16624803  
Structure of RhlG, an essential beta-ketoacyl reductase in the rhamnolipid biosynthetic pathway of Pseudomonas aeruginosa.
D.J.Miller, Y.M.Zhang, C.O.Rock, S.W.White.
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.
  Selected figure(s)  
Figure 5.
FIGURE 5. Interactions of RhlG with NADP^+. NADP^+ carbon bonds are green, and protein carbon bonds are colored gray. Hydrogen bonds are indicated with dashed lines.
Figure 6.
FIGURE 6. Electron density in the RhlG·NADP^+ active site. The electron density for the NADP^+ ligand, protein residues Ser^148, Tyr^162, and Lys^166, and proton relay waters (W )10 and 4 are shown for monomer A. The 2F[o] – F[c] map was contoured at 1 .
  The above figures are reprinted by permission from the ASBMB: J Biol Chem (2006, 281, 18025-18032) copyright 2006.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
21081168 D.Dutta, S.Bhattacharyya, S.Mukherjee, B.Saha, and A.K.Das (2011).
Crystal structure of FabG4 from Mycobacterium tuberculosis reveals the importance of C-terminal residues in ketoreductase activity.
  J Struct Biol, 174, 147-155.
PDB code: 3m1l
20738404 S.Heeb, M.P.Fletcher, S.R.Chhabra, S.P.Diggle, P.Williams, and M.Cámara (2011).
Quinolones: from antibiotics to autoinducers.
  FEMS Microbiol Rev, 35, 247-274.  
18326581 K.Zhu, and C.O.Rock (2008).
RhlA converts beta-hydroxyacyl-acyl carrier protein intermediates in fatty acid synthesis to the beta-hydroxydecanoyl-beta-hydroxydecanoate component of rhamnolipids in Pseudomonas aeruginosa.
  J Bacteriol, 190, 3147-3154.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB code is shown on the right.