PDBsum entry 1q7c

Oxidoreductase

PDB id: 1q7c

Contents

Protein chains

243 a.a. *

Ligands

NDP ×2

Waters ×60

* Residue conservation analysis

PDB id:

1q7c

Name:

Oxidoreductase

Title:

The structure of betaketoacyl-[acp] reductase y151f mutant in complex with NADPH fragment

Structure:

3-oxoacyl-[acyl-carrier protein] reductase. Chain: a, b. Synonym: betaketoacyl-[acp] reductase. 3-ketoacyl-acyl carrier protein reductase. Engineered: yes. Mutation: yes

Source:

Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli. Expression_system_taxid: 562.

Biol. unit:

Tetramer (from PDB file)

Resolution:

2.50Å R-factor: 0.215 R-free: 0.252

Authors:

A.C.Price,Y.-M.Zhang,C.O.Rock,S.M.White

Key ref:

A.C.Price et al. (2004). Cofactor-induced conformational rearrangements establish a catalytically competent active site and a proton relay conduit in FabG. Structure, 12, 417-428. PubMed id: 15016358 DOI: 10.1016/j.str.2004.02.008

Date:

17-Aug-03 Release date: 17-Feb-04

Protein chains

P0AEK2  (FABG_ECOLI) -  3-oxoacyl-[acyl-carrier-protein] reductase FabG from Escherichia coli (strain K12)

Seq: 244 a.a.

Struc: 243 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.1.1.1.100 - 3-oxoacyl-[acyl-carrier-protein] reductase.
• Reaction: a (3R)-hydroxyacyl-[ACP] + NADP⁺ = a 3-oxoacyl-[ACP] + NADPH + H⁺

(3R)-hydroxyacyl-[ACP] + NADP(+) (Bound ligand (Het Group name = NDP) matches with 64.58% similarity) = 3-oxoacyl-[ACP] + NADPH + H(+)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1016/j.str.2004.02.008

Structure 12:417-428 (2004)

PubMed id: 15016358

Cofactor-induced conformational rearrangements establish a catalytically competent active site and a proton relay conduit in FabG.

A.C.Price, Y.M.Zhang, C.O.Rock, S.W.White.

ABSTRACT

beta-Ketoacyl-acyl carrier protein reductase (FabG) is a key component in the type II fatty acid synthase system. The structures of Escherichia coli FabG and mutant in binary complexes with NADP(H) reveal that mechanistically important conformational changes accompany cofactor binding. The active site Ser-Tyr-Lys triad is repositioned into a catalytically competent constellation, and a hydrogen bonded network consisting of ribose hydroxyls, the Ser-Tyr-Lys triad, and four water molecules creates a proton wire to replenish the tyrosine proton donated during catalysis. Also, a disordered loop in FabG forms a substructure in the complex that shapes the entrance to the active site. A key observation is that the nicotinamide portion of the cofactor is disordered in the FabG[Y151F].NADP(H) complex, and Tyr151 appears to be necessary for is defective in NADPH binding. Finally, structural changes consistent with the observed negative cooperativity of FabG are described.

Selected figure(s)

Figure 5.
Figure 5. Structural Rearrangements Explain the Allosteric Behavior of FabG
In the two panels, the α helices of monomer A are orange, the β strands and coils of monomer A are yellow, the α helices of monomer B are blue, and the β strands and coils of monomer B are green.
(A) A close up of the FabG intermonomer interface at region “c” as defined in Figure 1B. Glu168′ from one monomer forms hydrogen bonds to the amide nitrogens of Leu95 and Met96 on the adjacent monomer, and residues N-terminal to Gly147 on the β5-α5 loop are disordered.
(B) A close up of the same region in the FabG·NADP^+ complex. Note that Glu168′ has shifted its hydrogen bond register to the amide nitrogens of Leu95 and Gly147, and the residues N-terminal to Gly147 on the β5-α5 loop are now ordered. The figure was produced using MOLSCRIPT (Kraulis, 1991) and rendered with RASTER3D (Merritt and Murphy, 1994).

Figure 8.
Figure 8. An Overview of the Interacting Monomers in the FabG·NADP^+ Complex
Glu168′ and its hydrogen bonding interactions, as depicted in Figure 5B, are shown at the interface. Shown in monomer A are the bound cofactor, the active site residues, the ordered β5-α5 loop (purple), and Asn145, which we propose may interact with the incoming pantetheine moiety of the ACP-bound substrate. Shown in monomer B are Arg129′ and Arg172′, which interact with the incoming ACP (Zhang et al., 2003b). The figure was produced using MOLSCRIPT (Kraulis, 1991) and rendered with RASTER3D (Merritt and Murphy, 1994).

The above figures are reprinted by permission from Cell Press: Structure (2004, 12, 417-428) copyright 2004.

Figures were selected by an automated process.