Structural determinants of cold activity and glucose tolerance of a family 1 glycoside hydrolase (GH1) from Antarctic Marinomonas sp. ef1.

Autor: Gourlay LJ; Department of Biosciences, University of Milano, Italy., Mangiagalli M; Department of Biotechnology and Biosciences, University of Milano-Bicocca, Italy., Moroni E; Institute of Chemical Sciences and Technologies, National Research Council of Italy, SCITE-CNR, Milan, Italy., Lotti M; Department of Biotechnology and Biosciences, University of Milano-Bicocca, Italy., Nardini M; Department of Biosciences, University of Milano, Italy.
Jazyk: angličtina
Zdroj: The FEBS journal [FEBS J] 2024 Jul; Vol. 291 (13), pp. 2897-2917. Date of Electronic Publication: 2024 Feb 23.
DOI: 10.1111/febs.17096
Abstrakt: Cold-active enzymes support life at low temperatures due to their ability to maintain high activity in the cold and can be useful in several biotechnological applications. Although information on the mechanisms of enzyme cold adaptation is still too limited to devise general rules, it appears that very diverse structural and functional changes are exploited in different protein families and within the same family. In this context, we studied the cold adaptation mechanism and the functional properties of a member of the glycoside hydrolase family 1 (GH1) from the Antarctic bacterium Marinomonas sp. ef1. This enzyme exhibits all typical functional hallmarks of cold adaptation, including high catalytic activity at 5 °C, broad substrate specificity, low thermal stability, and higher lability of the active site compared to the overall structure. Analysis of the here-reported crystal structure (1.8 Å resolution) and molecular dynamics simulations suggest that cold activity and thermolability may be due to a flexible region around the active site (residues 298-331), whereas the dynamic behavior of loops flanking the active site (residues 47-61 and 407-413) may favor enzyme-substrate interactions at the optimal temperature of catalysis (T opt ) by tethering together protein regions lining the active site. Stapling of the N-terminus onto the surface of the β-barrel is suggested to partly counterbalance protein flexibility, thus providing a stabilizing effect. The tolerance of the enzyme to glucose and galactose is accounted for by the presence of a "gatekeeping" hydrophobic residue (Leu178), located at the entrance of the active site.
(© 2024 Federation of European Biochemical Societies.)
Databáze: MEDLINE
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