Biochemical properties and phylogeny of hydroxypyruvate reductases from methanotrophic bacteria with different c1-assimilation pathways
| Autor: | S. Y. But, Yuri A. Trotsenko, S V Egorova, Valentina N. Khmelenina |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
biology Hydroxypyruvate reductase Glycerate dehydrogenase activity 030106 microbiology Biophysics Alphaproteobacteria Glyoxylate cycle macromolecular substances General Medicine biology.organism_classification Biochemistry Biochemistry Genetics and Molecular Biology (miscellaneous) Methylococcaceae Microbiology carbohydrates (lipids) Serine 03 medical and health sciences 030104 developmental biology bacteria Geriatrics and Gerontology Methylococcus capsulatus Betaproteobacteria |
| Zdroj: | Biochemistry (Moscow). 82:1295-1303 |
| ISSN: | 1608-3040 0006-2979 |
| DOI: | 10.1134/s0006297917110074 |
| Popis: | In the aerobic methanotrophic bacteria Methylomicrobium alcaliphilum 20Z, Methylococcus capsulatus Bath, and Methylosinus trichosporium OB3b, the biochemical properties of hydroxypyruvate reductase (Hpr), an indicator enzyme of the serine pathway for assimilation of reduced C1-compounds, were comparatively analyzed. The recombinant Hpr obtained by cloning and heterologous expression of the hpr gene in Escherichia coli catalyzed NAD(P)H-dependent reduction of hydroxypyruvate or glyoxylate, but did not catalyze the reverse reactions of D-glycerate or glycolate oxidation. The absence of the glycerate dehydrogenase activity in the methanotrophic Hpr confirmed a key role of the enzyme in utilization of C1-compounds via the serine cycle. The enzyme from Ms. trichosporium OB3b realizing the serine cycle as a sole assimilation pathway had much higher special activity and affinity in comparison to Hpr from Mm. alcaliphilum 20Z and Mc. capsulatus Bath assimilating carbon predominantly via the ribulose monophosphate (RuMP) cycle. The hpr gene was found as part of gene clusters coding the serine cycle enzymes in all sequenced methanotrophic genomes except the representatives of the Verrucomicrobia phylum. Phylogenetic analyses revealed two types of Hpr: (i) Hpr of methanotrophs belonging to the Gammaproteobacteria class, which use the serine cycle along with the RuMP cycle, as well as of non-methylotrophic bacteria belonging to the Alphaproteobacteria class; (ii) Hpr of methylotrophs from Alpha- and Betaproteobacteria classes that use only the serine cycle and of non-methylotrophic representatives of Betaproteobacteria. The putative role and origin of hydroxypyruvate reductase in methanotrophs are discussed. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|