5OCM

Imine Reductase from Streptosporangium roseum in complex with NADP+ and 2,2,2-trifluoroacetophenone hydrate

Summary for 5OCM

• Entry DOI: 10.2210/pdb5ocm/pdb
• Descriptor: NAD_Gly3P_dh, NAD-dependent glycerol-3-phosphate dehydrogenase, NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE, 2,2,2-trifluoromethyl acetophenone hydrate, ... (5 entities in total)
• Functional Keywords: imine, amine, nadph, oxidoreductase
• Biological source: Streptosporangium roseum
• Total number of polymer chains: 6
• Total formula weight: 186027.42

Authors

Sharma, M.,Nestl, B.,Grogan, G. (deposition date: 2017-07-03, release date: 2018-05-16, Last modification date: 2024-01-17)

Primary citation

Lenz, M.,Fademrecht, S.,Sharma, M.,Pleiss, J.,Grogan, G.,Nestl, B.M.
New imine-reducing enzymes from beta-hydroxyacid dehydrogenases by single amino acid substitutions.
Protein Eng. Des. Sel., 31:109-120, 2018

PubMed Abstract: We report the exploration of the evolutionary relationship between imine reductases (IREDs) and other dehydrogenases. This approach is informed by the sequence similarity between these enzyme families and the recently described promiscuous activity of IREDs for the highly reactive carbonyl compound 2,2,2-trifluoroacetophenone. Using the structure of the R-selective IRED from Streptosporangium roseum (R-IRED-Sr) as a model, β-hydroxyacid dehydrogenases (βHADs) were identified as the dehydrogenases most similar to IREDs. To understand how active site differences in IREDs and βHADs enable the reduction of predominantly C = N or C = O bonds respectively, we substituted amino acid residues in βHADs with the corresponding residues from the R-IRED-Sr and were able to increase the promiscuous activity of βHADs for C = N functions by a single amino acid substitution. Variants βHADAt_K170D and βHADAt_K170F lost mainly their keto acid reduction activity and gained the ability to catalyze the reduction of imines. Moreover, the product enantiomeric purity for a bulky imine substrate could be increased from 23% ee (R-IRED-Sr) to 97% ee (βHADAt_K170D/F_F231A) outcompeting already described IRED selectivity.

PubMed: 29733377
DOI: 10.1093/protein/gzy006

Experimental method

X-RAY DIFFRACTION (1.81 Å)