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651 a.a.
_CA
 D-galactose |
+ |
 O(2) |
= |
D-galacto-hexodialose |
+ |
 H(2)O(2) |
|---|
Key reference
DOI no: 10.1073/pnas.231463798 Proc Natl Acad Sci U S A 98:12932-12937 (2001) PubMed id: 11698678
Crystal structure of the precursor of galactose oxidase: an unusual self-processing enzyme. S.J.Firbank, M.S.Rogers, C.M.Wilmot, D.M.Dooley, M.A.Halcrow, P.F.Knowles, M.J.McPherson, S.E.Phillips. ABSTRACT
Galactose oxidase (EC ) is a monomeric enzyme that contains a single copper ion and catalyses the stereospecific oxidation of primary alcohols to their corresponding aldehydes. The protein contains an unusual covalent thioether bond between a tyrosine, which acts as a radical center during the two-electron reaction, and a cysteine. The enzyme is produced in a precursor form lacking the thioether bond and also possessing an additional 17-aa pro-sequence at the N terminus. Previous work has shown that the aerobic addition of Cu(2+) to the precursor is sufficient to generate fully processed mature enzyme. The structure of the precursor protein has been determined to 1.4 A, revealing the location of the pro-sequence and identifying structural differences between the precursor and the mature protein. Structural alignment of the precursor and mature forms of galactose oxidase shows that five regions of main chain and some key residues of the active site differ significantly between the two forms. The precursor structure provides a starting point for modeling the chemistry of thioether bond formation and pro-sequence cleavage.
Selected figure(s)
Figure 1.
Fig. 1. Structure of the mature form of galactose oxidase (Upper Left) and the precursor form (Upper Right). Domain I is red, domain II is blue, and domain III is purple. In the precursor form the N-terminal pro-sequence is green, and regions that differ from the mature structure by more than 2 Å are yellow. The sequence of galactose oxidase (14) is shown (Lower) and colored as above. The pro-sequence residues are numbered17 to
Figure 3.
Fig. 3. Active site residues in precursor galactose oxidase (Left) and in the mature protein (Center) showing the copper ligands (Tyr-272, Tyr-495, His-496, and His-581), Cys-228 that forms the thioether bond to Tyr-272, the tryptophan that stacks over it (Trp-290), and Phe-227. The Sof Cys-228 in the precursor is situated directly above C
[2] of Tyr-272. In the precursor the sulfur of the cysteine appears to have been oxidized to a sulfenic group. (Right) Final 2F[o]
Figures were selected by the author.
Literature references that cite this PDB file's key reference
PubMed id Reference
19373496 T.Kleffmann, S.A.Jongkees, G.Fairweather, S.M.Wilbanks, and G.N.Jameson (2009).
Mass-spectrometric characterization of two posttranslational modifications of cysteine dioxygenase.J Biol Inorg Chem, 14, 913-921.
18478142 A.John, M.M.Shaikh, and P.Ghosh (2008).
Structural and functional mimic of galactose oxidase by a copper complex of a sterically demanding [N2O2] ligand.Dalton Trans, 0, 2815-2824.
18330849 F.Escalettes, and N.J.Turner (2008).
Directed evolution of galactose oxidase: generation of enantioselective secondary alcohol oxidases.Chembiochem, 9, 857-860.
17024269 F.Michel, S.Hamman, F.Thomas, C.Philouze, I.Gautier-Luneau, and J.L.Pierre (2006).
Galactose Oxidase models: 19F NMR as a powerful tool to study the solution chemistry of tripodal ligands in the presence of copper(II).Chem Commun (Camb), 0, 4122-4124.
15997277 T.Nauser, G.Casi, W.H.Koppenol, and C.Schöneich (2005).
Intramolecular addition of cysteine thiyl radicals to phenylalanine in peptides: formation of cyclohexadienyl type radicals.Chem Commun (Camb), 0, 3400-3402.
14585973 D.D.Zhang, and M.Hannink (2003).
Distinct cysteine residues in Keap1 are required for Keap1-dependent ubiquitination of Nrf2 and for stabilization of Nrf2 by chemopreventive agents and oxidative stress.Mol Cell Biol, 23, 8137-8151.
11752422 J.P.Klinman (2001).
How many ways to craft a cofactor?Proc Natl Acad Sci U S A, 98, 14766-14768.
11698675 L.Xie, and W.A.van der Donk (2001).
Homemade cofactors: self-processing in galactose oxidase.Proc Natl Acad Sci U S A, 98, 12863-12865. The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time.
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