Substitution of one calcium-binding amino acid strengthens substrate binding in a thermophilic alginate lyase
| 发表年度： |
2018 |
| 期： |
3 |
| 卷： |
592 |
| 页： |
369-379 |
| 摘要： |
Ligand binding is sensitive to temperatures since noncovalent bonds between the binding site and ligand could be broken by heat. How metal ion-binding amino acids in alginate lyase evolve to achieve tight substrate binding in a hostile environment remains unknown. An endolytic alginate lyase AlgAT0 specifically cleaved the M-G glycosidic bond and released disaccharides as the main end product. Four conserved calcium-binding sites were predicted and the supplement of Ca2+ led to enhanced substrate binding and protein stability. Among the four conserved calcium-binding sites, one substitution of aspartate for glutamate in AlgAT0 was proved to stimulate Ca2+ affinity. This study suggested that substrate affinity of polysaccharide lyases could be improved by tight binding to Ca(2+)via one amino acid substitution. |
| 刊物名称： |
FEBS LETTERS |
| 影响因子： |
- |
