5UUO

Crystal structure of SARO_2595 from Novosphingobium aromaticivorans

Summary for 5UUO

• Entry DOI: 10.2210/pdb5uuo/pdb
• Descriptor: Glutathione S-transferase-like protein, GLUTATHIONE, SULFATE ION, ... (5 entities in total)
• Functional Keywords: bioenergy, glbrc, lignin valorization, transferase
• Biological source: Novosphingobium aromaticivorans (strain ATCC 700278 / DSM 12444 / CIP 105152 / NBRC 16084 / F199)
• Total number of polymer chains: 2
• Total formula weight: 67762.00

Authors

Bingman, C.A.,Kontur, W.S.,Olmsted, C.N.,Fox, B.G.,Donohue, T.J. (deposition date: 2017-02-17, release date: 2018-02-28, Last modification date: 2024-05-22)

Primary citation

Kontur, W.S.,Bingman, C.A.,Olmsted, C.N.,Wassarman, D.R.,Ulbrich, A.,Gall, D.L.,Smith, R.W.,Yusko, L.M.,Fox, B.G.,Noguera, D.R.,Coon, J.J.,Donohue, T.J.
Novosphingobium aromaticivoransuses a Nu-class glutathioneS-transferase as a glutathione lyase in breaking the beta-aryl ether bond of lignin.
J. Biol. Chem., 293:4955-4968, 2018

PubMed Abstract: As a major component of plant cell walls, lignin is a potential renewable source of valuable chemicals. Several sphingomonad bacteria have been identified that can break the β-aryl ether bond connecting most phenylpropanoid units of the lignin heteropolymer. Here, we tested three sphingomonads predicted to be capable of breaking the β-aryl ether bond of the dimeric aromatic compound guaiacylglycerol-β-guaiacyl ether (GGE) and found that metabolizes GGE at one of the fastest rates thus far reported. After the ether bond of racemic GGE is broken by replacement with a thioether bond involving glutathione, the glutathione moiety must be removed from the resulting two stereoisomers of the phenylpropanoid conjugate β-glutathionyl-γ-hydroxypropiovanillone (GS-HPV). We found that the Nu-class glutathione -transferase NaGST is the only enzyme needed to remove glutathione from both ()- and ()-GS-HPV in We solved the crystal structure of NaGST and used molecular modeling to propose a mechanism for the glutathione lyase (deglutathionylation) reaction in which an enzyme-stabilized glutathione thiolate attacks the thioether bond of GS-HPV, and the reaction proceeds through an enzyme-stabilized enolate intermediate. Three residues implicated in the proposed mechanism (Thr, Tyr, and Tyr) were found to be critical for the lyase reaction. We also found that Nu-class GSTs from sp. SYK-6 (which can also break the β-aryl ether bond) and (which cannot break the β-aryl ether bond) can also cleave ()- and ()-GS-HPV, suggesting that glutathione lyase activity may be common throughout this widespread but largely uncharacterized class of glutathione -transferases.

PubMed: 29449375
DOI: 10.1074/jbc.RA117.001268

Experimental method

X-RAY DIFFRACTION (1.25 Å)