Identification and Characterization of a Novel Carboxylesterase EstQ7 from a Soil Metagenomic Library
| Autor: | Luyao Wang, Yuzhi Tan, Zhenzhen Yan, Yingchen Zhang, Shuting Guo, Zhihong Xin, Liping Ding, Dandan Zou |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Biochemistry
Microbiology Pentapeptide repeat Carboxylesterase Substrate Specificity 03 medical and health sciences Catalytic triad Hydrolase Genetics Amino Acid Sequence Enzyme kinetics Molecular Biology Phylogeny Soil Microbiology 030304 developmental biology chemistry.chemical_classification Genomic Library 0303 health sciences 030306 microbiology Thermophile General Medicine Hydrogen-Ion Concentration Molecular Docking Simulation Enzyme chemistry Acyltransferase Metagenome |
| Popis: | A novel lipolytic gene, estq7, was identified from a fosmid metagenomic library. The recombinant enzyme EstQ7 consists of 370 amino acids with an anticipated molecular mass of 42 kDa. Multiple sequence alignments showed that EstQ7 contained a pentapeptide motif GHSMG, and a putative catalytic triad Ser174–Asp306–His344. Interestingly, EstQ7 was found to have very little similarity to the characterized lipolytic enzymes. Phylogenetic analysis revealed that EstQ7 may be a member of a novel family of lipolytic enzymes. Biochemical characterization of the recombinant enzyme revealed that it constitutes a slightly alkalophilic, moderate thermophilic and highly active carboxylesterase against short chain fatty acid esters with optimum temperature 50 ℃ and pH 8.2. The Km and kcat values toward p-nitrophenyl acetate were determined to be 0.17 mM and 1910 S-1, respectively. Moreover, EstQ7 was demonstrated to have acyltransferase activity by GC-MS analysis. Homology modeling of the three-dimensional structure of this new enzyme showed that it exhibits a typical α/β hydrolase fold, and the catalytic triad residues are spatially close. Molecular docking reveled the interactions between the enzyme and the ligand. The high levels of lipolytic activity of EstQ7, combined with its moderate thermophilic property, and acyltransferase activity, render this novel enzyme a promising candidate biocatalyst for food, pharmaceutical and biotechnological applications. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|