8CQG

Crystal Structure of a Chimeric Alpha-Amylase from Pseudoalteromonas Haloplanktis

Summary for 8CQG

• Entry DOI: 10.2210/pdb8cqg/pdb
• Descriptor: Alpha-amylase, 1,2-ETHANEDIOL, CHLORIDE ION, ... (5 entities in total)
• Functional Keywords: apo, alpha-amylase, hydrolase, chimeric
• Biological source: Pseudoalteromonas haloplanktis; More
• Total number of polymer chains: 1
• Total formula weight: 50023.77

Authors

Skagseth, S.,Lund, B.A.,Griese, J.J.,van der Ent, F.,Aqvist, J. (deposition date: 2023-03-06, release date: 2023-06-21, Last modification date: 2024-11-13)

Primary citation

van der Ent, F.,Skagseth, S.,Lund, B.A.,Socan, J.,Griese, J.J.,Brandsdal, B.O.,Aqvist, J.
Computational design of the temperature optimum of an enzyme reaction.
Sci Adv, 9:eadi0963-eadi0963, 2023

PubMed Abstract: Cold-adapted enzymes are characterized both by a higher catalytic activity at low temperatures and by having their temperature optimum down-shifted, compared to mesophilic orthologs. In several cases, the optimum does not coincide with the onset of protein melting but reflects some other type of inactivation. In the psychrophilic α-amylase from an Antarctic bacterium, the inactivation is thought to originate from a specific enzyme-substrate interaction that breaks around room temperature. Here, we report a computational redesign of this enzyme aimed at shifting its temperature optimum upward. A set of mutations designed to stabilize the enzyme-substrate interaction were predicted by computer simulations of the catalytic reaction at different temperatures. The predictions were verified by kinetic experiments and crystal structures of the redesigned α-amylase, showing that the temperature optimum is indeed markedly shifted upward and that the critical surface loop controlling the temperature dependence approaches the target conformation observed in a mesophilic ortholog.

PubMed: 37379391
DOI: 10.1126/sciadv.adi0963

Experimental method

X-RAY DIFFRACTION (1.74 Å)