{"id":{"repo_id":"east-anglia","oai_identifier":"oai:ueaeprints.uea.ac.uk:53417"},"canonical_url":"https://search.dev.ndltd.org/etd/east-anglia/oai:ueaeprints.uea.ac.uk:53417","repository":{"repo_id":"east-anglia","name":"University of East Anglia","base_url":"https://ueaeprints.uea.ac.uk/cgi/oai2"},"display":{"title":"Characterisation of OmcA From Shewanella oneidensis MR-1: Biophysical and Mineral Reduction Properties","abstract":"Several!Shewanella(spp!are!versatile!in!the!respiratory!substrates!they!use.! A! novel! set! of! respiratory! substrates! implicated! are! insoluble! Fe(III)! and! Mn(III,IV)! oxides.! OmcA! from! Shewanella( oneidensis( MR?1! plays! a! role! in! the! terminal!electron!transfer!during!respiratory!mineral!reduction,!but!has!minimal! or! contrasting! properties! in! the! literature.! A! suite! of! biophysical! techniques! confirmed!the!bis?histidine!axial!ligation!of!all!OmcA’s!haem!content!in!the!crystal! structure! and! in! solution.!The!paramagnetic! resonance! feature! designated! “LS3”! was!identified!to!be!unique!to!OmcA.!However!this!resonance!signal!is!modelled!to! be! produced! spin?coupling! and! not! unique! haem! ligation.! OmcA’s! electroactive! coverage!is!comparable!to!UndA!and!the!other!major!outer!membrane!multihaem! cytochrome!(OMMC)!clades!MtrC!and!MtrF!(i.e.!+0.08!V!to!?0.47!V!vs!S.H.E.).!The! crystal! structure! of! OmcA! shows! domain! fold,! domain! organisation! and! haem! orientation!conservation!with!MtrF!and!UndA.!Comprehensive!solution?structure! studies!of!OmcA!provided!contrasting!experimental!data!on!the!oligomeric!state!of! OmcA,!such!that!it!is!unresolved!whether!OmcA!forms!an!ion?sensitive!dimer.!The! crystal!structure!shows!a!predicted!mineral!interaction!peptide!(i.e.!T725P726S727)! is!solvent!exposed!and!would!putatively!bind!substrate!within!electron!tunneling! distance! of! a! terminal! haem.! Site?directed! mutagenesis! indicates! Thr725! is! significant! to! maintenance! of! the!molecular! environment! of! haem! 10.! Although! T725G!mutation!produces!a!≈80%!decrease!in!whole!cell!reduction!of!synthesised! hematite! over! 120! hours;! secondary! effects! of! change! in! haem! reduction! potentials! or!widespread! conformational! effects!were! ruled! out.!OmcA! has! thus! been!shown!to!share!a!common!OMMC?fold!and!exist!in!S.(oneidensis(MR?1!outer! membranes! as! a! functioning! mineral! reductase! cytochrome! with! unique! paramagnetic!resonance!properties!in!this!set!of!studies.!","abstract_html":"Several!Shewanella(spp!are!versatile!in!the!respiratory!substrates!they!use.! A! novel! set! of! respiratory! substrates! implicated! are! insoluble! Fe(III)! and! Mn(III,IV)! oxides.! OmcA! from! Shewanella( oneidensis( MR?1! plays! a! role! in! the! terminal!electron!transfer!during!respiratory!mineral!reduction,!but!has!minimal! or! contrasting! properties! in! the! literature.! A! suite! of! biophysical! techniques! confirmed!the!bis?histidine!axial!ligation!of!all!OmcA’s!haem!content!in!the!crystal! structure! and! in! solution.!The!paramagnetic! resonance! feature! designated! “LS3”! was!identified!to!be!unique!to!OmcA.!However!this!resonance!signal!is!modelled!to! be! produced! spin?coupling! and! not! unique! haem! ligation.! OmcA’s! electroactive! coverage!is!comparable!to!UndA!and!the!other!major!outer!membrane!multihaem! cytochrome!(OMMC)!clades!MtrC!and!MtrF!(i.e.!+0.08!V!to!?0.47!V!vs!S.H.E.).!The! crystal! structure! of! OmcA! shows! domain! fold,! domain! organisation! and! haem! orientation!conservation!with!MtrF!and!UndA.!Comprehensive!solution?structure! studies!of!OmcA!provided!contrasting!experimental!data!on!the!oligomeric!state!of! OmcA,!such!that!it!is!unresolved!whether!OmcA!forms!an!ion?sensitive!dimer.!The! crystal!structure!shows!a!predicted!mineral!interaction!peptide!(i.e.!T725P726S727)! is!solvent!exposed!and!would!putatively!bind!substrate!within!electron!tunneling! distance! of! a! terminal! haem.! Site?directed! mutagenesis! indicates! Thr725! is! significant! to! maintenance! of! the!molecular! environment! of! haem! 10.! Although! T725G!mutation!produces!a!≈80%!decrease!in!whole!cell!reduction!of!synthesised! hematite! over! 120! hours;! secondary! effects! of! change! in! haem! reduction! potentials! or!widespread! conformational! effects!were! ruled! out.!OmcA! has! thus! been!shown!to!share!a!common!OMMC?fold!and!exist!in!S.(oneidensis(MR?1!outer! membranes! as! a! functioning! mineral! reductase! cytochrome! with! unique! paramagnetic!resonance!properties!in!this!set!of!studies.!","abstract_has_math":false,"creators":["Baiden, Nanakow"],"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":2014,"date_issued":"2014-09","date_published":"2014-09","updated_at":"2026-07-24T02:12:08Z","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":["Baiden, Nanakow"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-09"]},{"key":"dc:date.issued","label":"Date","values":["2014-09"]},{"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/53417/"]},{"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/53417/1/NAB_Thesis.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Several!Shewanella(spp!are!versatile!in!the!respiratory!substrates!they!use.! A! novel! set! of! respiratory! substrates! implicated! are! insoluble! Fe(III)! and! Mn(III,IV)! oxides.! OmcA! from! Shewanella( oneidensis( MR?1! plays! a! role! in! the! terminal!electron!transfer!during!respiratory!mineral!reduction,!but!has!minimal! or! contrasting! properties! in! the! literature.! A! suite! of! biophysical! techniques! confirmed!the!bis?histidine!axial!ligation!of!all!OmcA’s!haem!content!in!the!crystal! structure! and! in! solution.!The!paramagnetic! resonance! feature! designated! “LS3”! was!identified!to!be!unique!to!OmcA.!However!this!resonance!signal!is!modelled!to! be! produced! spin?coupling! and! not! unique! haem! ligation.! OmcA’s! electroactive! coverage!is!comparable!to!UndA!and!the!other!major!outer!membrane!multihaem! cytochrome!(OMMC)!clades!MtrC!and!MtrF!(i.e.!+0.08!V!to!?0.47!V!vs!S.H.E.).!The! crystal! structure! of! OmcA! shows! domain! fold,! domain! organisation! and! haem! orientation!conservation!with!MtrF!and!UndA.!Comprehensive!solution?structure! studies!of!OmcA!provided!contrasting!experimental!data!on!the!oligomeric!state!of! OmcA,!such!that!it!is!unresolved!whether!OmcA!forms!an!ion?sensitive!dimer.!The! crystal!structure!shows!a!predicted!mineral!interaction!peptide!(i.e.!T725P726S727)! is!solvent!exposed!and!would!putatively!bind!substrate!within!electron!tunneling! distance! of! a! terminal! haem.! Site?directed! mutagenesis! indicates! Thr725! is! significant! to! maintenance! of! the!molecular! environment! of! haem! 10.! Although! T725G!mutation!produces!a!≈80%!decrease!in!whole!cell!reduction!of!synthesised! hematite! over! 120! hours;! secondary! effects! of! change! in! haem! reduction! potentials! or!widespread! conformational! effects!were! ruled! out.!OmcA! has! thus! been!shown!to!share!a!common!OMMC?fold!and!exist!in!S.(oneidensis(MR?1!outer! membranes! as! a! functioning! mineral! reductase! cytochrome! with! unique! paramagnetic!resonance!properties!in!this!set!of!studies.!"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Characterisation of OmcA From Shewanella oneidensis MR-1: Biophysical and Mineral Reduction Properties"]}]}],"canonical_facts":{"dc:creator":["Baiden, Nanakow"],"dc:date":["2014-09"],"dc:date.issued":["2014-09"],"dc:description.abstract":["Several!Shewanella(spp!are!versatile!in!the!respiratory!substrates!they!use.! A! novel! set! of! respiratory! substrates! implicated! are! insoluble! Fe(III)! and! Mn(III,IV)! oxides.! OmcA! from! Shewanella( oneidensis( MR?1! plays! a! role! in! the! terminal!electron!transfer!during!respiratory!mineral!reduction,!but!has!minimal! or! contrasting! properties! in! the! literature.! A! suite! of! biophysical! techniques! confirmed!the!bis?histidine!axial!ligation!of!all!OmcA’s!haem!content!in!the!crystal! structure! and! in! solution.!The!paramagnetic! resonance! feature! designated! “LS3”! was!identified!to!be!unique!to!OmcA.!However!this!resonance!signal!is!modelled!to! be! produced! spin?coupling! and! not! unique! haem! ligation.! OmcA’s! electroactive! coverage!is!comparable!to!UndA!and!the!other!major!outer!membrane!multihaem! cytochrome!(OMMC)!clades!MtrC!and!MtrF!(i.e.!+0.08!V!to!?0.47!V!vs!S.H.E.).!The! crystal! structure! of! OmcA! shows! domain! fold,! domain! organisation! and! haem! orientation!conservation!with!MtrF!and!UndA.!Comprehensive!solution?structure! studies!of!OmcA!provided!contrasting!experimental!data!on!the!oligomeric!state!of! OmcA,!such!that!it!is!unresolved!whether!OmcA!forms!an!ion?sensitive!dimer.!The! crystal!structure!shows!a!predicted!mineral!interaction!peptide!(i.e.!T725P726S727)! is!solvent!exposed!and!would!putatively!bind!substrate!within!electron!tunneling! distance! of! a! terminal! haem.! Site?directed! mutagenesis! indicates! Thr725! is! significant! to! maintenance! of! the!molecular! environment! of! haem! 10.! Although! T725G!mutation!produces!a!≈80%!decrease!in!whole!cell!reduction!of!synthesised! hematite! over! 120! hours;! secondary! effects! of! change! in! haem! reduction! potentials! or!widespread! conformational! effects!were! ruled! out.!OmcA! has! thus! been!shown!to!share!a!common!OMMC?fold!and!exist!in!S.(oneidensis(MR?1!outer! membranes! as! a! functioning! mineral! reductase! cytochrome! with! unique! paramagnetic!resonance!properties!in!this!set!of!studies.!"],"dc:format":["application/pdf"],"dc:identifier.uri":["https://ueaeprints.uea.ac.uk/id/eprint/53417/1/NAB_Thesis.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/53417/"],"dc:title":["Characterisation of OmcA From Shewanella oneidensis MR-1: Biophysical and Mineral Reduction Properties"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["phd"]},"updated_at":"2026-07-24T02:12:08Z"}