{"id":{"repo_id":"east-anglia","oai_identifier":"oai:ueaeprints.uea.ac.uk:42417"},"canonical_url":"https://search.dev.ndltd.org/etd/east-anglia/oai:ueaeprints.uea.ac.uk:42417","repository":{"repo_id":"east-anglia","name":"University of East Anglia","base_url":"https://ueaeprints.uea.ac.uk/cgi/oai2"},"display":{"title":"Genetic analysis of DMSP metabolism in the marine Roseobacter clade","abstract":"Genetic, biochemical, bioinformatic and molecular approaches were used to analyse microbial catabolism of dimethylsulfoniopropionate (DMSP), an abundant anti-stress compound made by marine phytoplankton. Members of the Roseobacter clade of marine α-proteobacteria may catabolise DMSP by two different routes; demethylation to form methylmercaptopropionate (MMPA), and cleavage by DMSP-lyases, yielding volatile dimethylsulfide (DMS) plus acrylate. The DMSP-lyase, DddP, was purified from Roseovarius nubinhibens ISM and characterised in vitro. Nuclear magnetic resonance spectroscopy and gas chromatography confirmed bona fide DMSP lyase activity and mutation of predicted active-site residues abolished DMS production. DddP was also detected in the fungal coral pathogen Aspergillus sydowii, likely acquired from bacteria by inter-Domain horizontal-gene-transfer. A new DMSP-lyase, DddW, was identified in another Roseobacter species, Ruegeria pomeroyi DSS-3, initially by microarray-based demonstrations that transcription of dddW was induced in cells grown with DMSP. An adjacent gene encoded the cognate transcriptional regulator. Escherichia coli cells that over-expressed DddW cleaved DMSP into DMS plus acrylate. Thus, Ruegeria pomeroyi has three DMSP-lyases, with DddP and DddQ being known already; mutational analyses showed that all three contributed to its DMSP-dependent DMS (Ddd+) phenotype. Moran’s laboratory had shown that the DMSP demethylase was encoded by R. pomeroyi dmdA. I unveiled intimate links between the demethylation and the cleavage pathway(s). A key player is acuI, which is co-transcribed with dmdA, both genes being induced by DMSP and, more markedly, the DMSP-catabolite, acrylate. Furthermore, AcuI- mutants failed to grow on acrylate as sole carbon source and were more sensitive to its toxic effects. AcuI- mutants failed to grow on DMSP so, surprisingly, Ruegeria likely uses lyase pathway(s) to grow on this compound. A potential regulatory gene, transcribed divergently from dmdA, was also identified. The microarray also, wholly unexpectedly, revealed a suite of cox genes involved in carbon monoxide oxidation that was up-regulated in response to DMS.","abstract_html":"Genetic, biochemical, bioinformatic and molecular approaches were used to analyse microbial catabolism of dimethylsulfoniopropionate (DMSP), an abundant anti-stress compound made by marine phytoplankton. Members of the Roseobacter clade of marine α-proteobacteria may catabolise DMSP by two different routes; demethylation to form methylmercaptopropionate (MMPA), and cleavage by DMSP-lyases, yielding volatile dimethylsulfide (DMS) plus acrylate. The DMSP-lyase, DddP, was purified from Roseovarius nubinhibens ISM and characterised in vitro. Nuclear magnetic resonance spectroscopy and gas chromatography confirmed bona fide DMSP lyase activity and mutation of predicted active-site residues abolished DMS production. DddP was also detected in the fungal coral pathogen Aspergillus sydowii, likely acquired from bacteria by inter-Domain horizontal-gene-transfer. A new DMSP-lyase, DddW, was identified in another Roseobacter species, Ruegeria pomeroyi DSS-3, initially by microarray-based demonstrations that transcription of dddW was induced in cells grown with DMSP. An adjacent gene encoded the cognate transcriptional regulator. Escherichia coli cells that over-expressed DddW cleaved DMSP into DMS plus acrylate. Thus, Ruegeria pomeroyi has three DMSP-lyases, with DddP and DddQ being known already; mutational analyses showed that all three contributed to its DMSP-dependent DMS (Ddd+) phenotype. Moran’s laboratory had shown that the DMSP demethylase was encoded by R. pomeroyi dmdA. I unveiled intimate links between the demethylation and the cleavage pathway(s). A key player is acuI, which is co-transcribed with dmdA, both genes being induced by DMSP and, more markedly, the DMSP-catabolite, acrylate. Furthermore, AcuI- mutants failed to grow on acrylate as sole carbon source and were more sensitive to its toxic effects. AcuI- mutants failed to grow on DMSP so, surprisingly, Ruegeria likely uses lyase pathway(s) to grow on this compound. A potential regulatory gene, transcribed divergently from dmdA, was also identified. The microarray also, wholly unexpectedly, revealed a suite of cox genes involved in carbon monoxide oxidation that was up-regulated in response to DMS.","abstract_has_math":false,"creators":["Kirkwood, Mark"],"institution":"University of East Anglia","degree_name":"phd","degree_level":"doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012","date_published":"2012","updated_at":"2026-07-24T02:11:54Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Kirkwood, Mark"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012"]},{"key":"dc:date.issued","label":"Date","values":["2012"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["School of Biological Sciences"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of East Anglia"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://ueaeprints.uea.ac.uk/id/eprint/42417/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["phd"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://ueaeprints.uea.ac.uk/id/eprint/42417/1/2012KirkwoodMPhD.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Genetic, biochemical, bioinformatic and molecular approaches were used to analyse microbial catabolism of dimethylsulfoniopropionate (DMSP), an abundant anti-stress compound made by marine phytoplankton. Members of the Roseobacter clade of marine α-proteobacteria may catabolise DMSP by two different routes; demethylation to form methylmercaptopropionate (MMPA), and cleavage by DMSP-lyases, yielding volatile dimethylsulfide (DMS) plus acrylate. The DMSP-lyase, DddP, was purified from Roseovarius nubinhibens ISM and characterised in vitro. Nuclear magnetic resonance spectroscopy and gas chromatography confirmed bona fide DMSP lyase activity and mutation of predicted active-site residues abolished DMS production. DddP was also detected in the fungal coral pathogen Aspergillus sydowii, likely acquired from bacteria by inter-Domain horizontal-gene-transfer. A new DMSP-lyase, DddW, was identified in another Roseobacter species, Ruegeria pomeroyi DSS-3, initially by microarray-based demonstrations that transcription of dddW was induced in cells grown with DMSP. An adjacent gene encoded the cognate transcriptional regulator. Escherichia coli cells that over-expressed DddW cleaved DMSP into DMS plus acrylate. Thus, Ruegeria pomeroyi has three DMSP-lyases, with DddP and DddQ being known already; mutational analyses showed that all three contributed to its DMSP-dependent DMS (Ddd+) phenotype. Moran’s laboratory had shown that the DMSP demethylase was encoded by R. pomeroyi dmdA. I unveiled intimate links between the demethylation and the cleavage pathway(s). A key player is acuI, which is co-transcribed with dmdA, both genes being induced by DMSP and, more markedly, the DMSP-catabolite, acrylate. Furthermore, AcuI- mutants failed to grow on acrylate as sole carbon source and were more sensitive to its toxic effects. AcuI- mutants failed to grow on DMSP so, surprisingly, Ruegeria likely uses lyase pathway(s) to grow on this compound. A potential regulatory gene, transcribed divergently from dmdA, was also identified. The microarray also, wholly unexpectedly, revealed a suite of cox genes involved in carbon monoxide oxidation that was up-regulated in response to DMS."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Genetic analysis of DMSP metabolism in the marine Roseobacter clade"]}]}],"canonical_facts":{"dc:creator":["Kirkwood, Mark"],"dc:date":["2012"],"dc:date.issued":["2012"],"dc:description.abstract":["Genetic, biochemical, bioinformatic and molecular approaches were used to analyse microbial catabolism of dimethylsulfoniopropionate (DMSP), an abundant anti-stress compound made by marine phytoplankton. Members of the Roseobacter clade of marine α-proteobacteria may catabolise DMSP by two different routes; demethylation to form methylmercaptopropionate (MMPA), and cleavage by DMSP-lyases, yielding volatile dimethylsulfide (DMS) plus acrylate. The DMSP-lyase, DddP, was purified from Roseovarius nubinhibens ISM and characterised in vitro. Nuclear magnetic resonance spectroscopy and gas chromatography confirmed bona fide DMSP lyase activity and mutation of predicted active-site residues abolished DMS production. DddP was also detected in the fungal coral pathogen Aspergillus sydowii, likely acquired from bacteria by inter-Domain horizontal-gene-transfer. A new DMSP-lyase, DddW, was identified in another Roseobacter species, Ruegeria pomeroyi DSS-3, initially by microarray-based demonstrations that transcription of dddW was induced in cells grown with DMSP. An adjacent gene encoded the cognate transcriptional regulator. Escherichia coli cells that over-expressed DddW cleaved DMSP into DMS plus acrylate. Thus, Ruegeria pomeroyi has three DMSP-lyases, with DddP and DddQ being known already; mutational analyses showed that all three contributed to its DMSP-dependent DMS (Ddd+) phenotype. Moran’s laboratory had shown that the DMSP demethylase was encoded by R. pomeroyi dmdA. I unveiled intimate links between the demethylation and the cleavage pathway(s). A key player is acuI, which is co-transcribed with dmdA, both genes being induced by DMSP and, more markedly, the DMSP-catabolite, acrylate. Furthermore, AcuI- mutants failed to grow on acrylate as sole carbon source and were more sensitive to its toxic effects. AcuI- mutants failed to grow on DMSP so, surprisingly, Ruegeria likely uses lyase pathway(s) to grow on this compound. A potential regulatory gene, transcribed divergently from dmdA, was also identified. The microarray also, wholly unexpectedly, revealed a suite of cox genes involved in carbon monoxide oxidation that was up-regulated in response to DMS."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://ueaeprints.uea.ac.uk/id/eprint/42417/1/2012KirkwoodMPhD.pdf"],"dc:language":["en"],"dc:publisher.department":["School of Biological Sciences"],"dc:publisher.institution":["University of East Anglia"],"dc:relation.isreferencedby":["https://ueaeprints.uea.ac.uk/id/eprint/42417/"],"dc:title":["Genetic analysis of DMSP metabolism in the marine Roseobacter clade"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["phd"]},"updated_at":"2026-07-24T02:11:54Z"}