PDBsum entry 1upc

Synthase

PDB id: 1upc

Contents

Protein chains

(+ 0 more) 559 a.a. *

Ligands

TPP ×6

SO4 ×12

Metals

_MG ×6

Waters ×852

* Residue conservation analysis

PDB id:

1upc

Name:

Synthase

Title:

Carboxyethylarginine synthase from streptomyces clavuligerus

Structure:

Carboxyethylarginine synthase. Chain: a, b, c, d, e, f. Engineered: yes

Source:

Streptomyces clavuligerus. Organism_taxid: 1901. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Biol. unit:

Tetramer (from PDB file)

Resolution:

2.45Å R-factor: 0.178 R-free: 0.216

Authors:

M.E.C.Caines,J.M.Elkins,K.S.Hewitson,C.J.Schofield

Key ref:

M.E.Caines et al. (2004). Crystal structure and mechanistic implications of N2-(2-carboxyethyl)arginine synthase, the first enzyme in the clavulanic acid biosynthesis pathway. J Biol Chem, 279, 5685-5692. PubMed id: 14623876 DOI: 10.1074/jbc.M310803200

Date:

29-Sep-03 Release date: 20-Nov-03

Protein chains

Q9LCV9  (CEAS_STRCL) -  N(2)-(2-carboxyethyl)arginine synthase from Streptomyces clavuligerus

Seq: 573 a.a.

Struc: 559 a.a.

Enzyme reactions

• Enzyme class: E.C.2.5.1.66 - N(2)-(2-carboxyethyl)arginine synthase.
• Pathway: Clavulanate Biosynthesis
• Reaction: D-glyceraldehyde 3-phosphate + L-arginine = N₂-(2-carboxyethyl)-L- arginine + phosphate + H⁺

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

reference

DOI no: 10.1074/jbc.M310803200

J Biol Chem 279:5685-5692 (2004)

PubMed id: 14623876

Crystal structure and mechanistic implications of N2-(2-carboxyethyl)arginine synthase, the first enzyme in the clavulanic acid biosynthesis pathway.

M.E.Caines, J.M.Elkins, K.S.Hewitson, C.J.Schofield.

ABSTRACT

The initial step in the biosynthesis of the clinically important beta-lactamase inhibitor clavulanic acid involves condensation of two primary metabolites, D-glyceraldehyde 3-phosphate and L-arginine, to give N2-(2-carboxyethyl)arginine, a beta-amino acid. This unusual N-C bond forming reaction is catalyzed by the thiamin diphosphate (ThP2)-dependent enzyme N2-(2-carboxyethyl)arginine synthase. Here we report the crystal structure of N2-(2-carboxyethyl)arginine synthase, complexed with ThP2 and Mg2+, to 2.35-A resolution. The structure was solved in two space groups, P2(1)2(1)2(1) and P2(1)2(1)2. In both, the enzyme is observed in a tetrameric form, composed of a dimer of two more tightly associated dimers, consistent with both mass spectrometric and gel filtration chromatography studies. Both ThP2 and Mg2+ cofactors are present at the active site, with ThP2 in a "V" conformation as in related enzymes. A sulfate anion is observed in the active site of the enzyme in a location proposed as a binding site for the phosphate group of the d-glyceraldehyde 3-phosphate substrate. The mechanistic implications of the active site arrangement are discussed, including the potential role of the aminopyrimidine ring of the ThP2. The structure will form a basis for future mechanistic and structural studies, as well as engineering aimed at production of alternative beta-amino acids.

Selected figure(s)

Figure 1.
FIG. 1. Biosynthetic pathway leading to clavulanic acid. BLS, -lactam synthetase; PAH, proclavaminate amidino hydrolase; CAS, clavaminic synthase; CAD, clavaldehyde dehydrogenase; 2-OG, 2-oxoglutarate.

Figure 2.
FIG. 2. Structure of the CEAS tetramer. The ThP[2] molecules are shown as a ball-and-stick representation.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2004, 279, 5685-5692) copyright 2004.

Figures were selected by an automated process.