Details zur Publikation |
| Kategorie | Textpublikation |
| Referenztyp | Zeitschriften |
| DOI | 10.1038/s41598-020-58873-z |
Lizenz  |
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| Titel (primär) | Identification and characterization of a bacterial core methionine synthase |
| Autor | Deobald, D.; Hanna, R.; Shahryari, S.; Layer, G.; Adrian, L. |
| Quelle | Scientific Reports |
| Erscheinungsjahr | 2020 |
| Department | ISOBIO; UBT |
| Band/Volume | 10 |
| Seite von | art. 2100 |
| Sprache | englisch |
| Supplements | https://static-content.springer.com/esm/art%3A10.1038%2Fs41598-020-58873-z/MediaObjects/41598_2020_58873_MOESM1_ESM.docx |
| UFZ Querschnittsthemen | ProVIS; |
| Abstract | Methionine synthases are essential enzymes for amino acid and methyl group metabolism in all domains of life. Here, we describe a putatively anciently derived type of methionine synthase yet unknown in bacteria, here referred to as core-MetE. The enzyme appears to represent a minimal MetE form and transfers methyl groups from methylcobalamin instead of methyl-tetrahydrofolate to homocysteine. Accordingly, it does not possess the tetrahydrofolate binding domain described for canonical bacterial MetE proteins. In Dehalococcoides mccartyi strain CBDB1, an obligate anaerobic, mesophilic, slowly growing organohalide-respiring bacterium, it is encoded by the locus cbdbA481. In line with the observation to not accept methyl groups from methyl-tetrahydrofolate, all known genomes of bacteria of the class Dehalococcoidia lack metF encoding for methylene-tetrahydrofolate reductase synthesizing methyl-tetrahydrofolate, but all contain a core-metE gene. We heterologously expressed core-MetECBDB in E. coli and purified the 38 kDa protein. Core-MetECBDB exhibited Michaelis-Menten kinetics with respect to methylcob(III)alamin (KM ≈ 240 µM) and L-homocysteine (KM ≈ 50 µM). Only methylcob(III)alamin was found to be active as methyl donor with a kcat ≈ 60 s−1. Core-MetECBDB did not functionally complement metE-deficient E. coli strain DH5α (ΔmetE::kan) suggesting that core-MetECBDB and the canonical MetE enzyme from E. coli have different enzymatic specificities also in vivo. Core-MetE appears to be similar to a MetE-ancestor evolved before LUCA (last universal common ancestor) using methylated cobalamins as methyl donor whereas the canonical MetE consists of a tandem repeat and might have evolved by duplication of the core-MetE and diversification of the N-terminal part to a tetrahydrofolate-binding domain. |
| dauerhafte UFZ-Verlinkung | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=22844 |
| Deobald, D., Hanna, R., Shahryari, S., Layer, G., Adrian, L. (2020): Identification and characterization of a bacterial core methionine synthase Sci. Rep. 10 , art. 2100 10.1038/s41598-020-58873-z |
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