Family Report for: Polyesterase-MGS0156-like

MGS0156 hydrolyzed polylactic acid (PLA), polycaprolactone, as well as bis(benzoyloxyethyl)-terephthalate. MGS0156 produced a mixture of lactic acid monomers, dimers, and higher oligomers as products with solid PLA as a substrate.

Title: Biodegradation mechanism of polycaprolactone by a novel esterase MGS0156: a QM/MM approach
Feng S, Yue Y, Chen J, Zhou J, Li Y, Zhang Q
Ref: Environ Sci Process Impacts, 22:2332, 2020 : PubMed
Abstract


ESTHER: Feng_2020_Environ.Sci.Process.Impacts_22_2332
PubMedSearch: Feng 2020 Environ.Sci.Process.Impacts 22 2332
PubMedID: 33146659
Gene_locus related to this paper: 9zzzz-A0A0G3FEJ8

Abstract

Nowadays micro-plastic pollution has become one of the most serious global environmental problems. A potential strategy in managing micro-plastic waste is enzyme-catalyzed degradation. MGS0156 is a hydrolase screened from environmental metagenomes, which can efficiently degrade commercial plastics such as polycaprolactone, polylactide, etc. Here a combined molecular dynamics, molecular mechanics Poisson-Boltzmann surface area, and quantum mechanics/molecular mechanism method was used to reveal the enzymatic depolymerization mechanism. By systematically analyzing the binding processes of nine oligomers (from a monomer to tetramer), we found that longer oligomers have relatively stronger binding energy. The degradation process involves two concerted elementary steps: triad-assisted nucleophilic attack and C-O bond cleavage. C-O bond cleavage is the rate determining step with an average barrier of 15.7 kcal mol-1, which is consistent with the experimentally determined kcat (1101 s-1, corresponds to 13.3 kcal mol-1). The electrostatic influence analysis of twenty amino acids highlights His231 and Asp237 as potential mutation targets for designing more efficient MGS0156 mutants.



        

Title: Screening and Characterization of Novel Polyesterases from Environmental Metagenomes with High Hydrolytic Activity against Synthetic Polyesters
Hajighasemi M, Tchigvintsev A, Nocek B, Flick R, Popovic A, Hai T, Khusnutdinova AN, Brown G, Xu X and Yakunin AF <11 more author(s)> Hajighasemi M, Tchigvintsev A, Nocek B, Flick R, Popovic A, Hai T, Khusnutdinova AN, Brown G, Xu X, Cui H, Anstett J, Chernikova TN, Bruls T, Le Paslier D, Yakimov MM, Joachimiak A, Golyshina OV, Savchenko A, Golyshin PN, Edwards EA, Yakunin AF (- 11)
Ref: Environ Sci Technol, 52:12388, 2018 : PubMed
Abstract


ESTHER: Hajighasemi_2018_Environ.Sci.Technol_52_12388
PubMedSearch: Hajighasemi 2018 Environ.Sci.Technol 52 12388
PubMedID: 30284819
Gene_locus related to this paper: 9zzzz-a0a0g3fj39, 9zzzz-a0a0g3fj48, 9zzzz-A0A0G3FEJ8, 9bact-a4uz10

Abstract

The continuous growth of global plastics production, including polyesters, has resulted in increasing plastic pollution and subsequent negative environmental impacts. Therefore, enzyme-catalyzed depolymerization of synthetic polyesters as a plastics recycling approach has become a focus of research. In this study, we screened over 200 purified uncharacterized hydrolases from environmental metagenomes and sequenced microbial genomes and identified at least 10 proteins with high hydrolytic activity against synthetic polyesters. These include the metagenomic esterases MGS0156 and GEN0105, which hydrolyzed polylactic acid (PLA), polycaprolactone, as well as bis(benzoyloxyethyl)-terephthalate. With solid PLA as a substrate, both enzymes produced a mixture of lactic acid monomers, dimers, and higher oligomers as products. The crystal structure of MGS0156 was determined at 1.95 A resolution and revealed a modified alpha/beta hydrolase fold, with a lid domain and highly hydrophobic active site. Mutational studies of MGS0156 identified the residues critical for hydrolytic activity against both polyester and monoester substrates, with two-times higher polyesterase activity in the MGS0156 L169A mutant protein. Thus, our work identified novel, highly active polyesterases in environmental metagenomes and provided molecular insights into their activity, thereby augmenting our understanding of enzymatic polyester hydrolysis.