PDBsum entry 1v2g

Hydrolase

PDB id: 1v2g

Contents

Protein chain

178 a.a. *

Ligands

SO4

IMD

OCA

Waters ×107

* Residue conservation analysis

PDB id:

1v2g

Name:

Hydrolase

Title:

The l109p mutant of e. Coli thioesterase i/protease i/lysophospholipase l1 (tap) in complexed with octanoic acid

Structure:

Acyl-coa thioesterase i. Chain: a. Engineered: yes. Mutation: yes

Source:

Escherichia coli. Organism_taxid: 562. Gene: tesa, apea, pldc. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Biol. unit:

Dimer (from PQS)

Resolution:

2.00Å R-factor: 0.225 R-free: 0.265

Authors:

Y.-C.Lo,S.-C.Lin,Y.-C.Liaw

Key ref:

Y.C.Lo et al. (2005). Substrate specificities of Escherichia coli thioesterase I/protease I/lysophospholipase L1 are governed by its switch loop movement. Biochemistry, 44, 1971-1979. PubMed id: 15697222 DOI: 10.1021/bi048109x

Date:

15-Oct-03 Release date: 14-Dec-04

Protein chain

P0ADA1  (TESA_ECOLI) -  Thioesterase 1/protease 1/lysophospholipase L1 from Escherichia coli (strain K12)

Seq: 208 a.a.

Struc: 178 a.a.*

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

Enzyme reactions

• Enzyme class 2: E.C.3.1.1.2 - arylesterase.
• Reaction: a phenyl acetate + H2O = a phenol + acetate + H⁺

phenyl acetate + H2O = phenol (Bound ligand (Het Group name = OCA) matches with 70.00% similarity) + acetate + H(+)

• Enzyme class 3: E.C.3.1.1.5 - lysophospholipase.
• Reaction: a 1-acyl-sn-glycero-3-phosphocholine + H2O = sn-glycerol 3-phosphocholine + a fatty acid + H⁺
• Enzyme class 4: E.C.3.1.2.14 - oleoyl-[acyl-carrier-protein] hydrolase.
• Reaction: (9Z)-octadecenoyl-[ACP] + H2O = (9Z)-octadecenoate + holo-[ACP] + H⁺
• Enzyme class 5: E.C.3.1.2.2 - palmitoyl-CoA hydrolase.
• Reaction: hexadecanoyl-CoA + H2O = hexadecanoate + CoA + H⁺

hexadecanoyl-CoA + H2O = hexadecanoate + CoA + H(+) (Bound ligand (Het Group name = OCA) matches with 55.56% similarity)

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

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

reference

DOI no: 10.1021/bi048109x

Biochemistry 44:1971-1979 (2005)

PubMed id: 15697222

Substrate specificities of Escherichia coli thioesterase I/protease I/lysophospholipase L1 are governed by its switch loop movement.

Y.C.Lo, S.C.Lin, J.F.Shaw, Y.C.Liaw.

ABSTRACT

Escherichia coli thioesterase I/protease I/lysophospholipase L(1) (TAP) is a multifunctional lysophospholipase and acyl-CoA thioesterase with a SGNH-hydrolase fold. The relationship between TAP's structure and its versatile substrate specificity, however, is unclear. Here, we present the crystal structure of TAP in complex with octanoic acid (TAP-OCA; OCA, a free fatty acid with eight carbon atoms, C(8)). A structural comparison of native TAP with TAP-OCA reveals a remarkable conformational change in loop(75)(-)(80), called "switch loop movement", upon OCA binding to the substrate-binding crevice of TAP. OCA binding to the substrate-binding crevice results in a continuous hydrophobic surface, which triggers switch loop movement. The switch loop movement is acyl chain length dependent, with an effect of stabilizing the Michaelis complex (MC) of TAP during catalysis, and is essential for TAP's substrate preference. The finding of a sulfate ion binding site in the TAP structures, together with previous enzyme kinetic analyses, leads us to postulate that a putative CoA binding site is essential for efficient catalysis of thioesters in TAP. We also present the crystal structure of L109P-OCA (TAP's L109P mutant in complex with OCA), in which Leu109 mutated to Pro109 abolishes switch loop movement. This result strengthens our hypothesis that the switch loop movement is induced by hydrophobic interactions.