PDBsum entry 1lkc

Lyase

PDB id: 1lkc

Contents

Protein chain

355 a.a. *

Ligands

PO4

PLP

EDO ×2

Waters ×215

* Residue conservation analysis

PDB id:

1lkc

Name:

Lyase

Title:

Crystal structure of l-threonine-o-3-phosphate decarboxylase from salmonella enterica

Structure:

L-threonine-o-3-phosphate decarboxylase. Chain: a. Synonym: cobd. Engineered: yes

Source:

Salmonella enterica. Organism_taxid: 28901. Gene: cobd. Expressed in: escherichia coli. Expression_system_taxid: 562

Biol. unit:

Dimer (from PDB file)

Resolution:

1.80Å R-factor: 0.203 R-free: 0.236

Authors:

C.G.Cheong,C.B.Bauer,K.R.Brushaber,J.C.Escalante-Semerena,I.Rayment

Key ref:

C.G.Cheong et al. (2002). Three-dimensional structure of the L-threonine-O-3-phosphate decarboxylase (CobD) enzyme from Salmonella enterica. Biochemistry, 41, 4798-4808. PubMed id: 11939774 DOI: 10.1021/bi012111w

Date:

24-Apr-02 Release date: 01-May-02

Supersedes:

1kus

Protein chain

P97084  (COBD_SALTY) -  Threonine-phosphate decarboxylase from Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)

Seq: 364 a.a.

Struc: 355 a.a.*

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

Enzyme reactions

• Enzyme class: E.C.4.1.1.81 - threonine-phosphate decarboxylase.
• Pathway: Corrin Biosynthesis (part 6)
• Reaction: O-phospho-L-threonine + H⁺ = (R)-1-aminopropan-2-yl phosphate + CO2

O-phospho-L-threonine + H(+) = (R)-1-aminopropan-2-yl phosphate + CO2 (Bound ligand (Het Group name = EDO) matches with 40.00% similarity)

• Cofactor: Pyridoxal 5'-phosphate

Pyridoxal 5'-phosphate (Bound ligand (Het Group name = PLP) matches with 93.75% similarity)

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

reference

DOI no: 10.1021/bi012111w

Biochemistry 41:4798-4808 (2002)

PubMed id: 11939774

Three-dimensional structure of the L-threonine-O-3-phosphate decarboxylase (CobD) enzyme from Salmonella enterica.

C.G.Cheong, C.B.Bauer, K.R.Brushaber, J.C.Escalante-Semerena, I.Rayment.

ABSTRACT

The three-dimensional structure of the pyridoxal 5'-phosphate (PLP)-dependent L-threonine-O-3-phosphate decarboxylase (CobD) from Salmonella enterica is described here. This enzyme is responsible for synthesizing (R)-1-amino-2-propanol phosphate which is the precursor for the linkage between the nucleotide loop and the corrin ring in cobalamin. The molecule is a molecular dimer where each subunit consists of a large and small domain. Overall the protein is very similar to the members of the family of aspartate aminotransferases. Indeed, the arrangement of the ligands surrounding the cofactor and putative substrate binding site are remarkably close to that observed in histidinol phosphate aminotransferase, which suggests that this latter enzyme might have been its progenitor. The only significant differences in structure occur at the N-terminus, which is approximately 12 residues shorter in CobD and does not form the same type of interdomain interaction common to other aminotransferases. CobD is unusual since within the aspartate aminotransferase subfamily of PLP-dependent enzymes the chemical transformations are substantially conserved, where the only exceptions are 1-aminocyclopropane-1-carboxylate synthase and CobD. Although there are a large number of PLP-dependent amino acid decarboxylases, these are generally larger and structurally distinct from the members of the aspartate aminotransferase subfamily of enzymes. The structure of CobD suggests that the chemical fate of the external aldimine can be redirected by modifications at the N-terminus of the protein. This study provides insight into the evolutionary history of the cobalamin biosynthetic pathway and raises the question of why most PLP-dependent decarboxylases are considerably larger enzymes.