PDBsum entry 2hgs

Amine/carboxylate ligase

PDB id: 2hgs

Contents

Protein chain

472 a.a. *

Ligands

SO4 ×2

ADP

GSH

Metals

_MG ×2

Waters ×230

* Residue conservation analysis

PDB id:

2hgs

Name:

Amine/carboxylate ligase

Title:

Human glutathione synthetase

Structure:

Protein (glutathione synthetase). Chain: a. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Organ: brain. Expressed in: escherichia coli. Expression_system_taxid: 562. Other_details: cdna

Biol. unit:

Homo-Dimer (from PDB file)

Resolution:

2.10Å R-factor: 0.218 R-free: 0.281

Authors:

G.Polekhina,P.Board,J.Rossjohn,M.W.Parker

Key ref:

G.Polekhina et al. (1999). Molecular basis of glutathione synthetase deficiency and a rare gene permutation event. EMBO J, 18, 3204-3213. PubMed id: 10369661 DOI: 10.1093/emboj/18.12.3204

Date:

04-Jan-99 Release date: 22-Jun-99

Protein chain

P48637  (GSHB_HUMAN) -  Glutathione synthetase from Homo sapiens

Seq: 474 a.a.

Struc: 472 a.a.

Enzyme reactions

• Enzyme class: E.C.6.3.2.3 - glutathione synthase.
• Reaction: gamma-L-glutamyl-L-cysteine + glycine + ATP = glutathione + ADP + phosphate + H⁺

gamma-L-glutamyl-L-cysteine + glycine + ATP = glutathione (Bound ligand (Het Group name = ADP) corresponds exactly) + ADP (Bound ligand (Het Group name = GSH) corresponds exactly) + phosphate + H(+)

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

reference

DOI no: 10.1093/emboj/18.12.3204

EMBO J 18:3204-3213 (1999)

PubMed id: 10369661

Molecular basis of glutathione synthetase deficiency and a rare gene permutation event.

G.Polekhina, P.G.Board, R.R.Gali, J.Rossjohn, M.W.Parker.

ABSTRACT

Glutathione synthetase (GS) catalyses the production of glutathione from gamma-glutamylcysteine and glycine in an ATP-dependent manner. Malfunctioning of GS results in disorders including metabolic acidosis, 5-oxoprolinuria, neurological dysfunction, haemolytic anaemia and in some cases is probably lethal. Here we report the crystal structure of human GS (hGS) at 2.1 A resolution in complex with ADP, two magnesium ions, a sulfate ion and glutathione. The structure indicates that hGS belongs to the recently identified ATP-grasp superfamily, although it displays no detectable sequence identity with other family members including its bacterial counterpart, Escherichia coli GS. The difficulty in identifying hGS as a member of the family is due in part to a rare gene permutation which has resulted in a circular shift of the conserved secondary structure elements in hGS with respect to the other known ATP-grasp proteins. Nevertheless, it appears likely that the enzyme shares the same general catalytic mechanism as other ligases. The possibility of cyclic permutations provides an insight into the evolution of this family and will probably lead to the identification of new members. Mutations that lead to GS deficiency have been mapped onto the structure, providing a molecular basis for understanding their effects.

Selected figure(s)

Figure 3.
Figure 3 A ribbon representation of the dimer. The dimerization unit of each monomer is shown in different colour and the lid domains shown in mauve. The GS deficiency mutations are shown in ball-and-stick. This figure was drawn with MOLSCRIPT (Kraulis, 1991).

Figure 4.
Figure 4 Comparison of human and bacterial GS. (A) Structure-based sequence alignment of hGS and ecGS. The secondary structure and residue numbering of hGS are shown above the alignment and the ecGS numbering below it. The secondary structure of the conserved structural core elements of the ATP-grasp superfamily are coloured as follows: the N-terminal domain is red, the middle, lid domain is green, the C-terminal domain is blue and the linker region (to the lid domain) in orange. Additional secondary structures found in hGS are shown in gray. Strictly conserved residues are highlighted in darkened boxes and invariant residues of GS enzymes from eukaryotic organisms are designated by asterisks. The complimentary mutations and cis-peptide regions discussed in the text are highlighted in the open boxes. The figure was produced using ALSCRIPT (Barton, 1993). (B and C) Topological diagrams highlighting the major structural elements of hGS and ecGS. The colours refer to the structural cores conserved throughout the ATP-grasp superfamily. (D and E) Ribbon diagrams of hGS and ecGS using the same colour coding as in (A). The ribbon figures were drawn with MOLSCRIPT (Kraulis, 1991).

The above figures are reprinted from an Open Access publication published by Macmillan Publishers Ltd: EMBO J (1999, 18, 3204-3213) copyright 1999.

Figures were selected by the author.