Metal ions and chloramphenicol inhibition of soluble methane monooxygenase from Methylosinus trichosporium OB3b

1996 ◽  
Vol 45 (6) ◽  
pp. 744-749 ◽  
Author(s):  
D. Jahng ◽  
T. K. Wood
Keyword(s):  
Metal Ions ◽  
Methane Monooxygenase ◽  
Methylosinus Trichosporium Ob3b ◽  
Methylosinus Trichosporium ◽  
Soluble Methane Monooxygenase

scholarly journals Methanobactin from Methylocystis sp. Strain SB2 Affects Gene Expression and Methane Monooxygenase Activity in Methylosinus trichosporium OB3b

2015 ◽  
Vol 81 (7) ◽  
pp. 2466-2473 ◽  
Author(s):  
Muhammad Farhan Ul-Haque ◽  
Bhagyalakshmi Kalidass ◽  
Alexey Vorobev ◽  
Bipin S. Baral ◽  
Alan A. DiSpirito ◽  
...  
Keyword(s):  
Gene Expression ◽  
Methane Monooxygenase ◽  
Particulate Methane Monooxygenase ◽  
Methylosinus Trichosporium Ob3b ◽  
Methylosinus Trichosporium ◽  
Monooxygenase Activity ◽  
Content Type ◽  
Soluble Methane Monooxygenase ◽  
A Subunit ◽  
Membrane Bound

ABSTRACTMethanotrophs can express a cytoplasmic (soluble) methane monooxygenase (sMMO) or membrane-bound (particulate) methane monooxygenase (pMMO). Expression of these MMOs is strongly regulated by the availability of copper. Many methanotrophs have been found to synthesize a novel compound, methanobactin (Mb), that is responsible for the uptake of copper, and methanobactin produced byMethylosinus trichosporiumOB3b plays a key role in controlling expression of MMO genes in this strain. As all known forms of methanobactin are structurally similar, it was hypothesized that methanobactin from one methanotroph may alter gene expression in another. WhenMethylosinus trichosporiumOB3b was grown in the presence of 1 μM CuCl2, expression ofmmoX, encoding a subunit of the hydroxylase component of sMMO, was very low.mmoXexpression increased, however, when methanobactin fromMethylocystissp. strain SB2 (SB2-Mb) was added, as did whole-cell sMMO activity, but there was no significant change in the amount of copper associated withM. trichosporiumOB3b. IfM. trichosporiumOB3b was grown in the absence of CuCl2, themmoXexpression level was high but decreased by several orders of magnitude if copper prebound to SB2-Mb (Cu-SB2-Mb) was added, and biomass-associated copper was increased. Exposure ofMethylosinus trichosporiumOB3b to SB2-Mb had no effect on expression ofmbnA, encoding the polypeptide precursor of methanobactin in either the presence or absence of CuCl2.mbnAexpression, however, was reduced when Cu-SB2-Mb was added in both the absence and presence of CuCl2. These data suggest that methanobactin acts as a general signaling molecule in methanotrophs and that methanobactin “piracy” may be commonplace.

Detection of soluble methane monooxygenase producing Methylosinus trichosporium OB3b by polymerase chain reaction

1994 ◽  
Vol 40 (11) ◽  
pp. 969-973 ◽  
Author(s):  
K. S. Mohan ◽  
Satish K. Walia
Keyword(s):  
Polymerase Chain Reaction ◽  
Dna Sequences ◽  
Methane Monooxygenase ◽  
Dna Fragments ◽  
Chain Reaction ◽  
Methylosinus Trichosporium Ob3b ◽  
Methylosinus Trichosporium ◽  
Soluble Methane Monooxygenase ◽  
Expected Length ◽  
Polymerase Chain

The soluble methane monooxygenase (sMMO) enzyme complex of methanotrophs cometabolizes haloaliphatic compounds such as trichloroethylene. Two 18-mer oligonucleotides as primary primers and a nested primer of the same length were selected to amplify specific DNA sequences of the sMMO gene cluster using polymerase chain reaction (PCR). Two DNA fragments of sizes 270 and 400 base pairs were obtained when purified DNA from the methanotroph Methylosinus trichosporium OB3b was used as template. The primers were specific for sMMO sequences of M. trichosporium, since none of the 13 bacterial isolates screened yielded the expected length of PCR-amplified DNA fragments. The detection limit of the PCR method was 5 × 102 cells of M. trichosporium. The sMMO sequences were successfully amplified in groundwater (containing native microbial population) when seeded with M. trichosporium, FP1 sense (5′-ATGTCCAGCGCTCATAAC-3′), RP1 antisense (5′-TCAGATGTCGGTCAGGGC-3′), FP2 sense nested (5′GCCATCATCGGTCAGGGC-3′), and FP2 sense nested (5′-GCCATCATCGAGGACATC-3′).Key words: detection, soluble methane monooxygenase, polymerase chain reaction, Methylosinus trichosporium OB3b.

scholarly journals Marker Exchange Mutagenesis ofmxaF, Encoding the Large Subunit of the Mxa Methanol Dehydrogenase, in Methylosinus trichosporium OB3b

2015 ◽  
Vol 82 (5) ◽  
pp. 1549-1555 ◽  
Author(s):  
Muhammad Farhan Ul Haque ◽  
Wenyu Gu ◽  
Alan A. DiSpirito ◽  
Jeremy D. Semrau
Keyword(s):  
Large Subunit ◽  
Methane Monooxygenase ◽  
Methanol Dehydrogenase ◽  
Methylosinus Trichosporium Ob3b ◽  
Initial Oxidation ◽  
Methylosinus Trichosporium ◽  
Content Type ◽  
Marker Exchange ◽  
Oxidation Of Methane ◽  
Soluble Methane Monooxygenase

ABSTRACTMethanotrophs have remarkable redundancy in multiple steps of the central pathway of methane oxidation to carbon dioxide. For example, it has been known for over 30 years that two forms of methane monooxygenase, responsible for oxidizing methane to methanol, exist in methanotrophs, i.e., soluble methane monooxygenase (sMMO) and particulate methane monooxygenase (pMMO), and that expression of these two forms is controlled by the availability of copper. Specifically, sMMO expression occurs in the absence of copper, while pMMO expression increases with increasing copper concentrations. More recently, it was discovered that multiple forms of methanol dehydrogenase (MeDH), Mxa MeDH and Xox MeDH, also exist in methanotrophs and that the expression of these alternative forms is regulated by the availability of cerium. That is, expression of Xox MeDH increases in the presence of cerium, while Mxa MeDH expression decreases in the presence of cerium. As it had been earlier concluded that pMMO and Mxa MeDH form a supercomplex in which electrons from Mxa MeDH are back donated to pMMO to drive the initial oxidation of methane, we speculated that Mxa MeDH could be rendered inactive through marker-exchange mutagenesis but growth on methane could still be possible if cerium was added to increase the expression of Xox MeDH under sMMO-expressing conditions. Here we report thatmxaF, encoding the large subunit of Mxa MeDH, could indeed be knocked out inMethylosinus trichosporiumOB3b, yet growth on methane was still possible, so long as cerium was added. Interestingly, growth of this mutant occurred in both the presence and the absence of copper, suggesting that Xox MeDH can replace Mxa MeDH regardless of the form of MMO expressed.

scholarly journals Homologous expression of soluble methane monooxygenase genes in Methylosinus trichosporium OB3b

Microbiology ◽  
1999 ◽  
Vol 145 (2) ◽  
pp. 461-470 ◽  
Author(s):  
John S. Lloyd ◽  
Ruth Finch ◽  
Howard Dalton ◽  
J. Colin Murrell
Keyword(s):  
Methane Monooxygenase ◽  
Methylosinus Trichosporium Ob3b ◽  
Methylosinus Trichosporium ◽  
Soluble Methane Monooxygenase ◽  
Homologous Expression

scholarly journals A TonB-Dependent Transporter Is Responsible for Methanobactin Uptake by Methylosinus trichosporium OB3b

2016 ◽  
Vol 82 (6) ◽  
pp. 1917-1923 ◽  
Author(s):  
Wenyu Gu ◽  
Muhammad Farhan Ul Haque ◽  
Bipin S. Baral ◽  
Erick A. Turpin ◽  
Nathan L. Bandow ◽  
...  
Keyword(s):  
Methane Monooxygenase ◽  
Copper Uptake ◽  
Wild Type ◽  
Particulate Methane Monooxygenase ◽  
Methylosinus Trichosporium Ob3b ◽  
Gene Encoding ◽  
Methylosinus Trichosporium ◽  
Content Type ◽  
Soluble Methane Monooxygenase ◽  
Genes Encoding

ABSTRACTMethanobactin, a small modified polypeptide synthesized by methanotrophs for copper uptake, has been found to be chromosomally encoded. The gene encoding the polypeptide precursor of methanobactin,mbnA, is part of a gene cluster that also includes several genes encoding proteins of unknown function (but speculated to be involved in methanobactin formation) as well asmbnT, which encodes a TonB-dependent transporter hypothesized to be responsible for methanobactin uptake. To determine ifmbnTis truly responsible for methanobactin uptake, a knockout was constructed inMethylosinus trichosporiumOB3b using marker exchange mutagenesis. The resultingM. trichosporiummbnT::Gmrmutant was found to be able to produce methanobactin but was unable to internalize it. Further, if this mutant was grown in the presence of copper and exogenous methanobactin, copper uptake was significantly reduced. Expression ofmmoXandpmoA, encoding polypeptides of the soluble methane monooxygenase (sMMO) and particulate methane monooxygenase (pMMO), respectively, also changed significantly when methanobactin was added, which indicates that the mutant was unable to collect copper under these conditions. Copper uptake and gene expression, however, were not affected in wild-typeM. trichosporiumOB3b, indicating that the TonB-dependent transporter encoded bymbnTis responsible for methanobactin uptake and that methanobactin is a key mechanism used by methanotrophs for copper uptake. When thembnT::Gmrmutant was grown under a range of copper concentrations in the absence of methanobactin, however, the phenotype of the mutant was indistinguishable from that of wild-typeM. trichosporiumOB3b, indicating that this methanotroph has multiple mechanisms for copper uptake.

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