8i01
From Proteopedia
Crystal structure of Escherichia coli glyoxylate carboligase
Structural highlights
FunctionGCL_ECOLI Catalyzes the condensation of two molecules of glyoxylate to give 2-hydroxy-3-oxopropanoate (also termed tartronate semialdehyde). Publication Abstract from PubMedA number of carboligases, which catalyze condensation of C1- and/or C2-aldehydes into multi-carbon products, have been reported. However, their catalytic activities and/or regioselectivities remained rather low. Thereby, this study has focused on engineering of C1 and C2 carboligases for the regioselective condensation of C1-formaldehyde into C4-erythrulose via C2-glycolaldehyde. The crystal structure of the glyoxylate carboligase from Escherichia coli (EcGCL) was elucidated in complex with glycolaldehyde. A structure-guided rationale generated several mutants, one of whose catalytic activity reached 15.6 M(-1).s(-1), almost 10 times greater than the wild-type enzyme. Another variant (i.e., EcGCL(_R484M/N283Q/L478M/M488L/R284K)) has shown significantly increased stability to the glycolaldehyde toxicity, enabling production of glycolaldehyde to 31 mM from 75 mM formaldehyde (conversion: 83 %). Besides, the E1 subunit of alpha-ketoglutarate dehydrogenase complex from Vibrio vulnificus (VvSucA) was engineered as a regiospecific C2 carboligase for condensation of glycolaldehyde into erythrulose. The combination of EcGCL(_R484M/N283Q/L478M/M488L/R284K) and VvSucA(_K228L) led to the cascade production of erythrulose to 8 mM from 90 mM formaldehyde via glycolaldehyde without byproduct formation. This study will contribute to valorization of C1 gases into industrially relevant multi-carbon products in an environment-friendly way. Engineering of two thiamine diphosphate-dependent enzymes for the regioselective condensation of C1-formaldehyde into C4-erythrulose.,Kim JH, Cheon H, Jo HJ, Kim JW, Kim GY, Seo HR, Seo PW, Kim JS, Park JB Int J Biol Macromol. 2023 Dec 31;253(Pt 8):127674. doi: , 10.1016/j.ijbiomac.2023.127674. Epub 2023 Oct 25. PMID:37890751[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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