PDBsum entry 2fs2

Hydrolase

PDB id: 2fs2

Contents

Protein chains

132 a.a. *

Ligands

SO4 ×3

Waters ×79

* Residue conservation analysis

PDB id:

2fs2

Name:

Hydrolase

Title:

Structure of the e. Coli paai protein from the phyenylacetic acid degradation operon

Structure:

Phenylacetic acid degradation protein paai. Chain: a, b. Engineered: yes

Source:

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

Biol. unit:

Dimer (from PDB file)

Resolution:

2.00Å R-factor: 0.187 R-free: 0.230

Authors:

R.Kniewel,J.A.Buglino,V.Solorzano,J.Wu,C.D.Lima,S.K.Burley,New York Sgx Research Center For Structural Genomics (Nysgxrc)

Key ref:

F.Song et al. (2006). Structure, function, and mechanism of the phenylacetate pathway hot dog-fold thioesterase PaaI. J Biol Chem, 281, 11028-11038. PubMed id: 16464851 DOI: 10.1074/jbc.M513896200

Date:

20-Jan-06 Release date: 07-Feb-06

Protein chains

P76084  (PAAI_ECOLI) -  Acyl-coenzyme A thioesterase PaaI from Escherichia coli (strain K12)

Seq: 140 a.a.

Struc: 132 a.a.*

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

Enzyme reactions

• Enzyme class: E.C.3.1.2.- - ?????

DOI no: 10.1074/jbc.M513896200

J Biol Chem 281:11028-11038 (2006)

PubMed id: 16464851

Structure, function, and mechanism of the phenylacetate pathway hot dog-fold thioesterase PaaI.

F.Song, Z.Zhuang, L.Finci, D.Dunaway-Mariano, R.Kniewel, J.A.Buglino, V.Solorzano, J.Wu, C.D.Lima.

ABSTRACT

The structure and biochemical function of the hot dog-fold thioesterase PaaI operative in the aerobic phenylacetate degradation pathway are examined. PaaI showed modest activity with phenylacetyl-coenzyme A, suggestive of a role in coenzyme A release from this pathway intermediate in the event of limiting downstream pathway enzymes. Minimal activity was observed with aliphatic acyl-coenzyme A thioesters, which ruled out PaaI function in the lower phenylacetate pathway. PaaI was most active with ring-hydroxylated phenylacetyl-coenzyme A thioesters. The x-ray crystal structure of the Escherichia coli thioesterase is reported and analyzed to define the structural basis of substrate recognition and catalysis. The contributions of catalytic and substrate binding residues, thus, identified were examined through steady-state kinetic analysis of site-directed mutant proteins.

Selected figure(s)

Figure 1.
FIGURE 1. The outline of a model of the phenylacetate pathway common to E. coli and A. evansii. 2-Hydroxyphenylacetate is isolated from the mutant lacking an active ring-opening enzyme (PaaG).

Figure 6.
FIGURE 6. Electrostatic surface picture illustrating the solvent exposure of E. coli PaaI active site. The active site is identified by the 4-hydroxyphenacyl-CoA ligand (yellow), which was positioned by superpositioning the PaaI structure with the structure of the Arthrobacter 4-HBA-CoA thioesterase (4-hydroxyphenacyl-CoA) complex (PDB code 1Q4T [PDB] ) (40). The picture was generated using the graphics program Pymol (69).

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2006, 281, 11028-11038) copyright 2006.

Figures were selected by an automated process.