Dataset Information

A mutagenic screen identifies a TonB-dependent receptor required for the lanthanide metal switch in the Type I methanotroph “Methylotuvimicrobium buryatense” 5GB1C

ABSTRACT: Several of the metabolic enzymes in methanotrophic bacteria rely on metals for both their expression and their catalysis. The MxaFI methanol dehydrogenase enzyme complex uses calcium as a cofactor to oxidize methanol, while the alternative methanol dehydrogenase XoxF uses lanthanide metals such as lanthanum and cerium for the same function. Lanthanide metals, abundant in the earth’s crust and widely used in electronic devices, strongly repress the transcription of mxaF yet activate the transcription of xoxF. This phenomenon of mxaF repression and xoxF activation in the presence of lanthanides is called the “lanthanide switch.” To better understand components of the lanthanide switch in the Type I gammaproteobacterial methanotroph “Methylotuvimicrobium buryatense” 5GB1C, we designed a mutagenesis system and selected for mutants unable to repress the mxaF promoter in the presence of lanthanum. Whole genome resequencing for multiple lanthanide switch mutants identified several unique point mutations in a single gene encoding a TonB-dependent receptor, which we have named LanA. While the LanA TonB-dependent receptor is absolutely required for the lanthanide switch, it does not affect lanthanum uptake by the bacterium. Deletion of a separate lanthanide-repressible gene encoding a TonB protein had no effect on the lanthanide switch or on lanthanum uptake. The discovery of this novel component of the lanthanide regulatory system highlights the complexity of this circuit and suggests further components are likely involved.

ORGANISM(S): Methylotuvimicrobium buryatense

PROVIDER: GSE125909 | GEO | 2019/05/21

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Methyloversatilis universalis FAM5 utilizes single carbon compounds such as methanol or methylated amines as a sole source of carbon and energy. Expression profiling reveals distinct sets of genes altered during growth on methanol vs methylamine. Growth on methanol results in activation of mdh2 and a number of known accessory proteins. As expected, all genes for N-methylglutamate pathway were induced during growth on methylated amine. Among other functions, responding to a switch from methanol to methylated amines, are a heme-containing amine dehydrogenase (QHNDH), a PQQ-dependent methanol dehydrogenase homologue, a distant homologue of formaldehyde activating enzyme (fae3), molybdenum containing formate dehydrogenase, a set of transporters homologues to urea/ammonium transporters and amino-acid permeases. Genes encoding the PQQ-dependent methanol dehydrogenase and associated cytochrome, the enzymes from the assimilatory H4F-dependent pathway, and the tungsten-containing aldehyde oxidoreductase were down-regulated during growth on methylamine. Genes essential for carbon assimilation (serine cycle) and H4MTP-pathway for formaldehyde oxidation show similar level of expression on both C1-carbon sources. Phenotypic analysis of mutants lacking functional QHNDH had no growth defect on C1-compounds. M. universalis FAM5 strain with the methylene-tetrahydrofolate dehydrogenase lesion, a key enzyme of the H4-folate pathway, were not able to use any C1-compound, methanol or methylated amines. Methyloversatilis universalis FAM5 possesses three homologs of the formaldehyde activating enzymes. The relative expression of two of the formaldehyde activating enzyme (fae1) and fae2 did not change after the shift from methanol to methylamine growth. The relative expression of the third homologs, fae3, was significantly upregulated by methylamine. Single and double fae 2 and fae 3 mutants display similar to wild type growth M-BM- on methanol or methylamine. Strains lacking fae1 lost the ability to grow on both C1-compounds. However upon incubation on methylated amines the fae1-mutant produce revertants (fae1R ). The revertant strains displayed an impaired growth on methylamine but were not able to use methanol. Double mutations in fae1RM-BM- / fae3 or fae1R/fae2 and triple mutant fae1R/fae2/fae3 showed similar to fae1R phenotype. The metabolic pathways for utilization methanol and methylamine in Methyloversatilis universalis FAM5 are reconstructed. Methyloversatilis universalis FAM5 grown on methanol and methylamine with two biologial replicates for each condition. RNA-Seq was used for transcriptomics.

Project description:Methyloversatilis universalis FAM5 utilizes single carbon compounds such as methanol or methylated amines as a sole source of carbon and energy. Expression profiling reveals distinct sets of genes altered during growth on methanol vs methylamine. Growth on methanol results in activation of mdh2 and a number of known accessory proteins. As expected, all genes for N-methylglutamate pathway were induced during growth on methylated amine. Among other functions, responding to a switch from methanol to methylated amines, are a heme-containing amine dehydrogenase (QHNDH), a PQQ-dependent methanol dehydrogenase homologue, a distant homologue of formaldehyde activating enzyme (fae3), molybdenum containing formate dehydrogenase, a set of transporters homologues to urea/ammonium transporters and amino-acid permeases. Genes encoding the PQQ-dependent methanol dehydrogenase and associated cytochrome, the enzymes from the assimilatory H4F-dependent pathway, and the tungsten-containing aldehyde oxidoreductase were down-regulated during growth on methylamine. Genes essential for carbon assimilation (serine cycle) and H4MTP-pathway for formaldehyde oxidation show similar level of expression on both C1-carbon sources. Phenotypic analysis of mutants lacking functional QHNDH had no growth defect on C1-compounds. M. universalis FAM5 strain with the methylene-tetrahydrofolate dehydrogenase lesion, a key enzyme of the H4-folate pathway, were not able to use any C1-compound, methanol or methylated amines. Methyloversatilis universalis FAM5 possesses three homologs of the formaldehyde activating enzymes. The relative expression of two of the formaldehyde activating enzyme (fae1) and fae2 did not change after the shift from methanol to methylamine growth. The relative expression of the third homologs, fae3, was significantly upregulated by methylamine. Single and double fae 2 and fae 3 mutants display similar to wild type growth on methanol or methylamine. Strains lacking fae1 lost the ability to grow on both C1-compounds. However upon incubation on methylated amines the fae1-mutant produce revertants (fae1R ). The revertant strains displayed an impaired growth on methylamine but were not able to use methanol. Double mutations in fae1R / fae3 or fae1R/fae2 and triple mutant fae1R/fae2/fae3 showed similar to fae1R phenotype. The metabolic pathways for utilization methanol and methylamine in Methyloversatilis universalis FAM5 are reconstructed.

Dataset Information

A mutagenic screen identifies a TonB-dependent receptor required for the lanthanide metal switch in the Type I methanotroph “Methylotuvimicrobium buryatense” 5GB1C

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets