DB code: S00431

RLCP classification	1.14.10105.1251 : Hydrolysis
CATH domain	3.60.15.10 : Metallo-beta-lactamase; Chain A	Catalytic domain
E.C.	3.1.2.6
CSA	1qh5
M-CSA	1qh5
MACiE	M0157

CATH domain	Related DB codes (homologues)
3.60.15.10 : Metallo-beta-lactamase; Chain A	S00515 S00432

Uniprot Enzyme Name
UniprotKB	Protein name	Synonyms	RefSeq	Pfam
Q16775	Hydroxyacylglutathione hydrolase	EC 3.1.2.6 Glyoxalase II Glx II	NP_001035517.1 (Protein) NM_001040427.1 (DNA/RNA sequence) NP_005317.2 (Protein) NM_005326.4 (DNA/RNA sequence)	PF00753 (Lactamase_B) [Graphical View]

KEGG enzyme name
hydroxyacylglutathione hydrolase glyoxalase II S-2-hydroxylacylglutathione hydrolase hydroxyacylglutathione hydrolase acetoacetylglutathione hydrolase

UniprotKB: Accession Number	Entry name	Activity	Subunit	Subcellular location	Cofactor
Q16775	GLO2_HUMAN	S-(2-hydroxyacyl)glutathione + H(2)O = glutathione + a 2-hydroxy carboxylate.	Monomer.		Binds 2 zinc ions per subunit.

KEGG Pathways
Map code	Pathways	E.C.
MAP00620	Pyruvate metabolism

Compound table
	Cofactors	Substrates		Products		Intermediates
KEGG-id	C00038	C03899	C00001	C00051	C02929
E.C.
Compound	Zinc	S-(2-Hydroxyacyl)glutathione	H2O	Glutathione	2-Hydroxycarboxylate
Type	heavy metal	amino acids,carbohydrate,carboxyl group,peptide/protein,sulfide group	H2O	amino acids,carboxyl group,peptide/protein,sulfhydryl group	carbohydrate,carboxyl group
ChEBI	29105 29105		15377 15377	16856 16856
PubChem	32051 32051		22247451 962 22247451 962	124886 25246407 124886 25246407

1qh3A	Bound:2x_ZN	Unbound		Unbound	Unbound	Analogue:CAC
1qh3B	Bound:2x_ZN	Unbound		Unbound	Unbound	Analogue:CAC
1qh5A	Bound:2x_ZN	Unbound		Bound:GTT	Unbound	Unbound
1qh5B	Bound:2x_ZN	Analogue:GBP		Unbound	Unbound	Unbound

Reference for Active-site residues
resource	references	E.C.
Swiss-prot & PDB

Active-site residues
PDB	Catalytic residues	Cofactor-binding residues	Modified residues	Main-chain involved in catalysis	Comment

1qh3A		HIS 54;HIS 56;HIS 110(Zinc-1 binding);ASP 134(both zinc binding);ASP 58;HIS 59;ASP 134;HIS 173(Zinc-2 binding)
1qh3B		HIS 54;HIS 56;HIS 110(Zinc-1 binding);ASP 134(both zinc binding);ASP 58;HIS 59;ASP 134;HIS 173(Zinc-2 binding)
1qh5A		HIS 54;HIS 56;HIS 110(Zinc-1 binding);ASP 134(both zinc binding);ASP 58;HIS 59;ASP 134;HIS 173(Zinc-2 binding)
1qh5B		HIS 54;HIS 56;HIS 110(Zinc-1 binding);ASP 134(both zinc binding);ASP 58;HIS 59;ASP 134;HIS 173(Zinc-2 binding)

References for Catalytic Mechanism
References	Sections	No. of steps in catalysis
[1]	Fig.8, p.1074-1076	2

References
[1]
Resource
Comments	X-ray crystallography (1.9/1.45 Angstroms)
Medline ID
PubMed ID	10508780
Journal	Structure Fold Des
Year	1999
Volume	7
Pages	1067-78
Authors	Cameron AD, Ridderstrom M, Olin B, Mannervik B
Title	Crystal structure of human glyoxalase II and its complex with a glutathione thiolester substrate analogue.
Related PDB	1qh3 1qh5
Related UniProtKB	Q16775
[2]
Resource
Comments	Active site mutation
Medline ID
PubMed ID	11018726
Journal	Biochim Biophys Acta
Year	2000
Volume	1481
Pages	344-8
Authors	Ridderstrom M, Jemth P, Cameron AD, Mannervik B
Title	The active-site residue tyr-175 in human glyoxalase II contributes to binding of glutathione derivatives.
Related PDB
Related UniProtKB

Comments
According to the literature [1], the reaction is thought to involve a nucleophilic attack on the C1 atom of the substrate. Presumably, the interaction of the water molecule with the two zinc ions, would lower its pKa sufficiently for it to exist in the form of a hydroxide and alleviate the need for a base to abstract a proton. Asp58 will help orient the hydroxide for attack and modify its pKa. The nucleophilic attack on C1 atom of the substrate would presumably result in a negatively charged tetrahedral intermediate. Putative transition-state structure with both oxygen atoms interacting with zinc-1. To complete the interaction, the C1-S bond must be broken, the glutathione protonated and the products must diffuse from the active site to be replaced by water molecules. Without further information, it is difficult to describe how it occurs. However, the sulphur atoms of the substrate analogue or product, glutathione are close enough from zinc-2. Thus, one possibility is that the zinc ion will stabilise a thiolate ion formed upon bond cleavage [1].

Comments

According to the literature [1], the reaction is thought to involve a nucleophilic attack on the C1 atom of the substrate. Presumably, the interaction of the water molecule with the two zinc ions, would lower its pKa sufficiently for it to exist in the form of a hydroxide and alleviate the need for a base to abstract a proton. Asp58 will help orient the hydroxide for attack and modify its pKa. The nucleophilic attack on C1 atom of the substrate would presumably result in a negatively charged tetrahedral intermediate. Putative transition-state structure with both oxygen atoms interacting with zinc-1. To complete the interaction, the C1-S bond must be broken, the glutathione protonated and the products must diffuse from the active site to be replaced by water molecules. Without further information, it is difficult to describe how it occurs. However, the sulphur atoms of the substrate analogue or product, glutathione are close enough from zinc-2. Thus, one possibility is that the zinc ion will stabilise a thiolate ion formed upon bond cleavage [1].

Created	Updated
2002-09-06	2009-02-26