SEARCH FOR HOMOLOGOUS ENZYMES TO PETASE IN DIFFERENT ENVIRONMENTAL SAMPLES

Inadequate handling of plastic waste poses an environmental challenge, particularly as microplastics have adverse effects on organisms, including humans. PET hydrolase (PETase) from Ideonella sakaiensis degrades PET with limited stability and productivity. Studies on the structure-function relationship of enzymes and advanced modeling are revolutionizing plastic degradation. Therefore, the objective is to search for PETase homologous enzymes in different metagenomic samples for biotechnological applications in microplastic degradation. In the first stage, the search of information about Ideonella sakaiensis PETase [A0A0K8P6T7], available in UniProt, in was retrieved from different databases (NCBI, KEGG, PDB, CDD, SMART, STRING, and WGS metagenomic projects - env_nr). In the second stage, homologous enzymes were sought in metagenomic samples available in MGnify, MetaCyc, and KEGG MGENES. Alignments were performed using Clustal Omega, and 3D modeling with MHOLline and Modeller, followed by analyses using Procheck, Prosa, PyMol, and Chimera. MetaCyc resulted in 13 pathways with variations in the expectation value (e-value) ranging from 1e-76 to 9.8, representing metabolic routes and biochemical processes in different organisms. In MGnify, 2399 sequences with matches were found. Among them, 49.40% were from aquatic environments, 37.18% from marine environments, 7.42% from soil, and 6.05% from freshwater environments. KEGG MGENES provided 500 sequences related to PETase in different metagenomes. In WGS metagenomic projects - env_nr, 85 enzymes were obtained, with 6% characterized and 94% with unknown function. Using MHOLline, we obtained 3D structures for all 85 enzymes. The next steps involve the structural characterization of these enzymes and comparative analysis among them.