PDBsum entry 1ca7

Cytokine

PDB id: 1ca7

Contents

Protein chains

114 a.a. *

Ligands

EN1 ×3

Waters ×18

* Residue conservation analysis

PDB id:

1ca7

Name:

Cytokine

Title:

Macrophage migration inhibitory factor (mif) with hydroxphenylpyruvate

Structure:

Protein (macrophage migration inhibitory factor). Chain: a, b, c. Synonym: mif, glycosylation-inhibiting factor. Engineered: yes. Other_details: complexed with hydroxyphenylpyruvate

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Biol. unit:

Trimer (from PDB file)

Resolution:

2.50Å R-factor: 0.200 R-free: 0.263

Authors:

J.B.Lubetsky,E.Lolis

Key ref:

J.B.Lubetsky et al. (1999). Pro-1 of macrophage migration inhibitory factor functions as a catalytic base in the phenylpyruvate tautomerase activity. Biochemistry, 38, 7346-7354. PubMed id: 10353846 DOI: 10.1021/bi990306m

Date:

25-Feb-99 Release date: 30-Jun-99

Protein chains

P14174  (MIF_HUMAN) -  Macrophage migration inhibitory factor from Homo sapiens

Seq: 115 a.a.

Struc: 114 a.a.

Enzyme reactions

• Enzyme class 2: E.C.5.3.2.1 - phenylpyruvate tautomerase.
• Reaction: 3-phenylpyruvate = enol-phenylpyruvate

3-phenylpyruvate = enol-phenylpyruvate (Bound ligand (Het Group name = EN1) matches with 92.31% similarity)

• Enzyme class 3: E.C.5.3.3.12 - L-dopachrome isomerase.

Pathway:

• Reaction: L-dopachrome = 5,6-dihydroxyindole-2-carboxylate

L-dopachrome (Bound ligand (Het Group name = EN1) matches with 80.00% similarity) = 5,6-dihydroxyindole-2-carboxylate

• Cofactor: Zn(2+)

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

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

reference

DOI no: 10.1021/bi990306m

Biochemistry 38:7346-7354 (1999)

PubMed id: 10353846

Pro-1 of macrophage migration inhibitory factor functions as a catalytic base in the phenylpyruvate tautomerase activity.

J.B.Lubetsky, M.Swope, C.Dealwis, P.Blake, E.Lolis.

ABSTRACT

Macrophage migration inhibitory factor (MIF) is an important immunoregulatory molecule with a unique ability to suppress the anti-inflammatory effects of glucocorticoids. Although considered a cytokine, MIF possesses a three-dimensional structure and active site similar to those of 4-oxalocrotonate tautomerase and 5-carboxymethyl-2-hydroxymuconate isomerase. Moreover, a number of catalytic activities have been defined for MIF. To gain insight into the role of catalysis in the biological function of MIF, we have begun to characterize the catalytic activities in more detail. Here we report the crystal structure of MIF complexed with p-hydroxyphenylpyruvate, a substrate for the phenylpyruvate tautomerase activity of MIF. The three binding sites for p-hydroxyphenylpyruvate in the MIF trimer lie at the interface between two subunits. The substrate interacts with Pro-1, Lys-32, and Ile-64 from one subunit and Tyr-95 and Asn-97 from an adjacent subunit. Pro-1 is positioned to function as a catalytic base. There is no functional group that polarizes the alpha-carbonyl of the substrate to weaken the adjacent C-H bond. Mutation of Pro-1 to glycine substantially reduces the catalytic activity. The insertion of an alanine between Pro-1 and Met-2 essentially abolishes activity. Structural studies of these mutants define a source of the reduced activity and provide insight into the mechanism of the catalytic reaction.