3HGJ

Old Yellow Enzyme from Thermus scotoductus SA-01 complexed with p-hydroxy-benzaldehyde

Summary for 3HGJ

• Entry DOI: 10.2210/pdb3hgj/pdb
• Related: 3HF3
• Descriptor: Chromate reductase, FLAVIN MONONUCLEOTIDE, P-HYDROXYBENZALDEHYDE, ... (4 entities in total)
• Functional Keywords: tim barrel, oxidoreductase
• Biological source: Thermus scotoductus
• Total number of polymer chains: 4
• Total formula weight: 154417.34

Authors

Opperman, D.J.,Sewell, B.T.,Litthauer, D.,Isupov, M.N.,Littlechild, J.A.,van Heerden, E. (deposition date: 2009-05-14, release date: 2010-02-23, Last modification date: 2024-03-20)

Primary citation

Opperman, D.J.,Sewell, B.T.,Litthauer, D.,Isupov, M.N.,Littlechild, J.A.,van Heerden, E.
Crystal structure of a thermostable old yellow enzyme from Thermus scotoductus SA-01
Biochem.Biophys.Res.Commun., 393:426-431, 2010

PubMed Abstract: Recent characterization of the chromate reductase (CrS) from the thermophile Thermus scotoductus SA-01 revealed this enzyme to be related to the Old Yellow Enzyme (OYE) family. Here, we report the structure of a thermostable OYE homolog in its holoform at 2.2A as well as its complex with p-hydroxybenzaldehyde (pHBA). The enzyme crystallized as octamers with the monomers showing a classical TIM barrel fold which upon dimerization yields the biologically active form of the protein. A sulfate ion is bound above the si-side of the non-covalently bound FMN cofactor in the oxidized solved structure but is displaced upon pHBA binding. The active-site architecture is highly conserved as with other members of this enzyme family. The pHBA in the CrS complex is positioned by hydrogen bonding to the two conserved catalytic-site histidines. The most prominent structural difference between CrS and other OYE homologs is the size of the "capping domain". Thermostabilization of the enzyme is achieved in part through increased proline content within loops and turns as well as increased intersubunit interactions through hydrogen bonding and complex salt bridge networks. CrS is able to reduce the C=C bonds of alpha,beta-unsaturated carbonyl compounds with a preference towards cyclic substrates however no activity was observed towards beta-substituted substrates. Mutational studies have confirmed the role of Tyr177 as the proposed proton donor although reduction could still occur at a reduced rate when this residue was mutated to phenylalanine.

PubMed: 20138824
DOI: 10.1016/j.bbrc.2010.02.011

Experimental method

X-RAY DIFFRACTION (2 Å)