7Y8C

Crystal structure of CotA laccase complexed with syringaldehyde

Summary for 7Y8C

• Entry DOI: 10.2210/pdb7y8c/pdb
• Related: 7Y8B
• Descriptor: Spore coat protein A, COPPER (II) ION, TRIETHYLENE GLYCOL, ... (5 entities in total)
• Functional Keywords: laccase, oxidoreductase
• Biological source: Bacillus subtilis subsp. subtilis str. 168
• Total number of polymer chains: 2
• Total formula weight: 117990.29

Authors

Liu, Z.C.,Xie, T.,Wang, G.G. (deposition date: 2022-06-23, release date: 2023-06-28, Last modification date: 2024-10-09)

Primary citation

Li, J.,Liu, Z.,Zhao, J.,Wang, G.,Xie, T.
Molecular insights into substrate promiscuity of CotA laccase catalyzing lignin-phenol derivatives.
Int.J.Biol.Macromol., 256:128487-128487, 2023

PubMed Abstract: CotA laccases are multicopper oxidases known for promiscuously oxidizing a broad range of substrates. However, studying substrate promiscuity is limited by the complexity of electron transfer (ET) between substrates and laccases. Here, a systematic analysis of factors affecting ET including electron donor acceptor coupling (Η), driving force (ΔG) and reorganization energy (λ) was done. Catalysis rates of syringic acid (SA), syringaldehyde (SAD) and acetosyringone (AS) (kcat(SAD) > kcat(SA) > kcat(AS)) are not entirely dependent on the ability to form phenol radicals indicated by ΔG and λ calculated by Density Functional Theory (SA < SAD ≈ AS). In determined CotA/SA and CotA/SAD structures, SA and SAD bound at 3.9 and 3.7 Å away from T1 Cu coordinating His419 ensuring a similar Η. Abilities of substrate to form phenol radicals could mainly account for difference between kcat(SAD) and kcat(SA). Furthermore, substrate pocket is solvent exposed at the para site of substrate's phenol hydroxyl, which would destabilize binding of AS in the same orientation and position resulting in low kcat. Our results indicated shallow partially covered binding site with propensity of amino acids distribution might help CotA discriminate lignin-phenol derivatives. These findings give new insights for developing specific catalysts for industrial application.

PubMed: 38042324
DOI: 10.1016/j.ijbiomac.2023.128487

Experimental method

X-RAY DIFFRACTION (2 Å)