9EH6 image
Deposition Date 2024-11-22
Release Date 2025-02-26
Last Version Date 2025-07-02
Entry Detail
PDB ID:
9EH6
Keywords:
Title:
Crystal Structure of AroC
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.25 Å
R-Value Free:
0.24
R-Value Work:
0.18
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Alpha/beta hydrolase fold-5 domain-containing protein
Gene (Uniprot):CLDAP_20430
Chain IDs:A, B
Chain Length:230
Number of Molecules:2
Biological Source:Caldilinea aerophila
Primary Citation
Mining Thermophile Genomes for New PETases with Exceptional Thermostabilities Using Sequence Similarity Networks.
Chembiochem 26 ? ? (2025)
PMID: 40069109 DOI: 10.1002/cbic.202500065

Abstact

Enzymatic hydrolysis of polyethylene terephthalate (PET) is a promising technology for advancing a circular PET economy. Several PET-degrading α/β hydrolases have been identified, but the full potential of this enzyme family to catalyze PET hydrolysis remains largely unexplored. To address this, sequence similarity networks were employed to investigate the α/β hydrolase fold-5 subfamily (IPR029059) for new PETases. Priority was given to sequences from thermophiles, as thermostable enzymes are likely more suitable for industrial applications. Ten enzymes with ~20% sequence identity to the well-known LCC-PETase were identified, and seven were successfully overexpressed and purified for in vitro characterization. Each enzyme catalyzed the hydrolysis of p-nitrophenyl butyrate, a mimic of trimeric PET, and emulsified PET nanoparticles. Notably, three enzymes were also capable of hydrolyzing PET films. Novel PETases exhibited melting temperatures (Tm) exceeding 55 °C and only modest losses of activity after incubation at 70 °C for 24 hours. The crystal structure of AroC (Tm = 85 °C) was resolved to 2.2 Å, revealing several salt bridges that likely confer thermostability, and a unique loop that is conserved amongst the PETases described here. These novel enzymes will enable engineering campaigns to generate thermostable and catalytically efficient PETases for use as industrial biocatalysts.

Legend

Protein

Chemical

Disease

Primary Citation of related structures