PDBsum entry 1t5h

Ligase

PDB id: 1t5h

Contents

Protein chain

498 a.a. *

Metals

_CA

Waters ×340

* Residue conservation analysis

PDB id:

1t5h

Name:

Ligase

Title:

4-chlorobenzoyl-coa ligase/synthetase unliganded, selenomethionine

Structure:

4-chlorobenzoyl coa ligase. Chain: x. Engineered: yes. Mutation: yes

Source:

Alcaligenes sp. Al3007. Organism_taxid: 206162. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.00Å R-factor: 0.184 R-free: 0.206

Authors:

A.M.Gulick,X.Lu,D.Dunaway-Mariano

Key ref:

A.M.Gulick et al. (2004). Crystal structure of 4-chlorobenzoate:CoA ligase/synthetase in the unliganded and aryl substrate-bound states. Biochemistry, 43, 8670-8679. PubMed id: 15236575 DOI: 10.1021/bi049384m

Date:

04-May-04 Release date: 03-Aug-04

Protein chain

Q8GN86  (Q8GN86_9BURK) -  4-chlorobenzoyl CoA ligase from Alcaligenes sp. AL3007

Seq: 504 a.a.

Struc: 498 a.a.

Enzyme reactions

• Enzyme class: E.C.6.2.1.33 - 4-chlorobenzoate--CoA ligase.
• Reaction: 4-chlorobenzoate + ATP + CoA = 4-chlorobenzoyl-CoA + AMP + diphosphate
• Cofactor: Mg(2+)

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

reference

DOI no: 10.1021/bi049384m

Biochemistry 43:8670-8679 (2004)

PubMed id: 15236575

Crystal structure of 4-chlorobenzoate:CoA ligase/synthetase in the unliganded and aryl substrate-bound states.

A.M.Gulick, X.Lu, D.Dunaway-Mariano.

ABSTRACT

4-Chlorobenzoate:CoA ligase (CBAL) is a member of a family of adenylate-forming enzymes that catalyze two-step adenylation and thioester-forming reactions. In previous studies, we have provided structural evidence that members of this enzyme family (exemplified by acetyl-CoA synthetase) use a large domain rotation to catalyze the respective partial reactions [A. M. Gulick, V. J. Starai, A. R. Horswill, K. M. Homick, and J. C. Escalante-Semerena, (2003) Biochemistry 42, 2866-2873]. CBAL catalyzes the synthesis of 4-chlorobenzoyl-CoA, the first step in the 4-chlorobenzoate degredation pathway in PCB-degrading bacteria. We have solved the 2.0 A crystal structure of the CBAL enzyme from Alcaligenes sp. AL3007 using multiwavelength anomalous dispersion. The results demonstrate that in the absence of any ligands, or bound to the aryl substrate 4-chlorobenzoate, the enzyme adopts the conformation poised for catalysis of the adenylate-forming half-reaction. We hypothesize that coenzyme A binding is required for stabilization of the alternate conformation, which catalyzes the 4-CBA-CoA thioester-forming reaction. We have also determined the structure of the enzyme bound to the aryl substrate 4-chlorobenzoate. The aryl binding pocket is composed of Phe184, His207, Val208, Val209, Phe249, Ala280, Ile303, Gly305, Met310, and Asn311. The structure of the 4-chlorobenzoate binding site is discussed in the context of the binding sites of other family members to gain insight into substrate specificity and evolution of new function.