Cargando…
Kinetic Characterization and Catalytic Mechanism of N-Acetylornithine Aminotransferase Encoded by slr1022 Gene from Synechocystis sp. PCC6803
The enzyme encoded by slr1022 gene from Synechocystis sp. PCC6803 was reported to function as N-acetylornithine aminotransferase, γ-aminobutyric acid aminotransferase, and ornithine aminotransferase, which played important roles in multiple metabolic pathways. Among these functions, N-acetylornithin...
Autores principales: | , , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10057298/ https://www.ncbi.nlm.nih.gov/pubmed/36982927 http://dx.doi.org/10.3390/ijms24065853 |
_version_ | 1785016328053063680 |
---|---|
author | Li, Zhi-Min Bai, Fumei Wang, Xiaoqin Xie, Congcong Wan, Yuting Li, Yating Liu, Jianping Li, Zhimin |
author_facet | Li, Zhi-Min Bai, Fumei Wang, Xiaoqin Xie, Congcong Wan, Yuting Li, Yating Liu, Jianping Li, Zhimin |
author_sort | Li, Zhi-Min |
collection | PubMed |
description | The enzyme encoded by slr1022 gene from Synechocystis sp. PCC6803 was reported to function as N-acetylornithine aminotransferase, γ-aminobutyric acid aminotransferase, and ornithine aminotransferase, which played important roles in multiple metabolic pathways. Among these functions, N-acetylornithine aminotransferase catalyzes the reversible conversion of N-acetylornithine to N-acetylglutamate-5-semialdehyde with PLP as cofactor, which is a key step in the arginine biosynthesis pathway. However, the investigation of the detailed kinetic characteristics and catalytic mechanism of Slr1022 has not been carried out yet. In this study, the exploration of kinetics of recombinant Slr1022 illustrated that Slr1022 mainly functioned as N-acetylornithine aminotransferase with low substrate specificity to γ-aminobutyric acid and ornithine. Kinetic assay of Slr1022 variants and the model structure of Slr1022 with N-acetylornithine-PLP complex revealed that Lys280 and Asp251 residues were the key amino acids of Slr1022. The respective mutation of the above two residues to Ala resulted in the activity depletion of Slr1022. Meanwhile, Glu223 residue was involved in substrate binding and it served as a switch between the two half reactions. Other residues such as Thr308, Gln254, Tyr39, Arg163, and Arg402 implicated a substrate recognition and catalytic process of the reaction. The results of this study further enriched the understanding of the catalytic kinetics and mechanism of N-acetylornithine aminotransferase, especially from cyanobacteria. |
format | Online Article Text |
id | pubmed-10057298 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-100572982023-03-30 Kinetic Characterization and Catalytic Mechanism of N-Acetylornithine Aminotransferase Encoded by slr1022 Gene from Synechocystis sp. PCC6803 Li, Zhi-Min Bai, Fumei Wang, Xiaoqin Xie, Congcong Wan, Yuting Li, Yating Liu, Jianping Li, Zhimin Int J Mol Sci Article The enzyme encoded by slr1022 gene from Synechocystis sp. PCC6803 was reported to function as N-acetylornithine aminotransferase, γ-aminobutyric acid aminotransferase, and ornithine aminotransferase, which played important roles in multiple metabolic pathways. Among these functions, N-acetylornithine aminotransferase catalyzes the reversible conversion of N-acetylornithine to N-acetylglutamate-5-semialdehyde with PLP as cofactor, which is a key step in the arginine biosynthesis pathway. However, the investigation of the detailed kinetic characteristics and catalytic mechanism of Slr1022 has not been carried out yet. In this study, the exploration of kinetics of recombinant Slr1022 illustrated that Slr1022 mainly functioned as N-acetylornithine aminotransferase with low substrate specificity to γ-aminobutyric acid and ornithine. Kinetic assay of Slr1022 variants and the model structure of Slr1022 with N-acetylornithine-PLP complex revealed that Lys280 and Asp251 residues were the key amino acids of Slr1022. The respective mutation of the above two residues to Ala resulted in the activity depletion of Slr1022. Meanwhile, Glu223 residue was involved in substrate binding and it served as a switch between the two half reactions. Other residues such as Thr308, Gln254, Tyr39, Arg163, and Arg402 implicated a substrate recognition and catalytic process of the reaction. The results of this study further enriched the understanding of the catalytic kinetics and mechanism of N-acetylornithine aminotransferase, especially from cyanobacteria. MDPI 2023-03-19 /pmc/articles/PMC10057298/ /pubmed/36982927 http://dx.doi.org/10.3390/ijms24065853 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Li, Zhi-Min Bai, Fumei Wang, Xiaoqin Xie, Congcong Wan, Yuting Li, Yating Liu, Jianping Li, Zhimin Kinetic Characterization and Catalytic Mechanism of N-Acetylornithine Aminotransferase Encoded by slr1022 Gene from Synechocystis sp. PCC6803 |
title | Kinetic Characterization and Catalytic Mechanism of N-Acetylornithine Aminotransferase Encoded by slr1022 Gene from Synechocystis sp. PCC6803 |
title_full | Kinetic Characterization and Catalytic Mechanism of N-Acetylornithine Aminotransferase Encoded by slr1022 Gene from Synechocystis sp. PCC6803 |
title_fullStr | Kinetic Characterization and Catalytic Mechanism of N-Acetylornithine Aminotransferase Encoded by slr1022 Gene from Synechocystis sp. PCC6803 |
title_full_unstemmed | Kinetic Characterization and Catalytic Mechanism of N-Acetylornithine Aminotransferase Encoded by slr1022 Gene from Synechocystis sp. PCC6803 |
title_short | Kinetic Characterization and Catalytic Mechanism of N-Acetylornithine Aminotransferase Encoded by slr1022 Gene from Synechocystis sp. PCC6803 |
title_sort | kinetic characterization and catalytic mechanism of n-acetylornithine aminotransferase encoded by slr1022 gene from synechocystis sp. pcc6803 |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10057298/ https://www.ncbi.nlm.nih.gov/pubmed/36982927 http://dx.doi.org/10.3390/ijms24065853 |
work_keys_str_mv | AT lizhimin kineticcharacterizationandcatalyticmechanismofnacetylornithineaminotransferaseencodedbyslr1022genefromsynechocystissppcc6803 AT baifumei kineticcharacterizationandcatalyticmechanismofnacetylornithineaminotransferaseencodedbyslr1022genefromsynechocystissppcc6803 AT wangxiaoqin kineticcharacterizationandcatalyticmechanismofnacetylornithineaminotransferaseencodedbyslr1022genefromsynechocystissppcc6803 AT xiecongcong kineticcharacterizationandcatalyticmechanismofnacetylornithineaminotransferaseencodedbyslr1022genefromsynechocystissppcc6803 AT wanyuting kineticcharacterizationandcatalyticmechanismofnacetylornithineaminotransferaseencodedbyslr1022genefromsynechocystissppcc6803 AT liyating kineticcharacterizationandcatalyticmechanismofnacetylornithineaminotransferaseencodedbyslr1022genefromsynechocystissppcc6803 AT liujianping kineticcharacterizationandcatalyticmechanismofnacetylornithineaminotransferaseencodedbyslr1022genefromsynechocystissppcc6803 AT lizhimin kineticcharacterizationandcatalyticmechanismofnacetylornithineaminotransferaseencodedbyslr1022genefromsynechocystissppcc6803 |