4U5R

Crystal structure of D106A mutant of RhCC (YP_702633.1) from Rhodococcus jostii RHA1 at 1.55 Angstrom

Summary for 4U5R

• Entry DOI: 10.2210/pdb4u5r/pdb
• Descriptor: RhCC, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL (3 entities in total)
• Functional Keywords: beta-alpha-beta structural motif, magnesium binding enzyme, tautomerase superfamily, isomerase
• Biological source: Rhodococcus jostii
• Total number of polymer chains: 3
• Total formula weight: 53045.66

Authors

Poddar, H.,Rozeboom, H.J.,Thunnissen, A.M.W.H. (deposition date: 2014-07-25, release date: 2015-02-25, Last modification date: 2023-12-20)

Primary citation

Baas, B.J.,Poddar, H.,Geertsema, E.M.,Rozeboom, H.J.,de Vries, M.P.,Permentier, H.P.,Thunnissen, A.M.,Poelarends, G.J.
Functional and structural characterization of an unusual cofactor-independent oxygenase.
Biochemistry, 54:1219-1232, 2015

PubMed Abstract: The vast majority of characterized oxygenases use bound cofactors to activate molecular oxygen to carry out oxidation chemistry. Here, we show that an enzyme of unknown activity, RhCC from Rhodococcus jostii RHA1, functions as an oxygenase, using 4-hydroxyphenylenolpyruvate as a substrate. This unique and complex reaction yields 3-hydroxy-3-(4-hydroxyphenyl)-pyruvate, 4-hydroxybenzaldehyde, and oxalic acid as major products. Incubations with H2(18)O, (18)O2, and a substrate analogue suggest that this enzymatic oxygenation reaction likely involves a peroxide anion intermediate. Analysis of sequence similarity and the crystal structure of RhCC (solved at 1.78 Å resolution) reveal that this enzyme belongs to the tautomerase superfamily. Members of this superfamily typically catalyze tautomerization, dehalogenation, or decarboxylation reactions rather than oxygenation reactions. The structure shows the absence of cofactors, establishing RhCC as a rare example of a redox-metal- and coenzyme-free oxygenase. This sets the stage to study the mechanistic details of cofactor-independent oxygen activation in the unusual context of the tautomerase superfamily.

PubMed: 25565350
DOI: 10.1021/bi501200j

Experimental method

X-RAY DIFFRACTION (1.55 Å)