title: Two propanediol utilization-like proteins of Moorella thermoacetica with phosphotransacetylase activity.
abstract: Moorella thermoacetica is one of the model acetogenic bacteria for the resolution of the Wood-Ljungdahl (acetyl-CoA) pathway in which CO2 is autotrophically assimilated yielding acetyl-CoA as central intermediate. Its further conversion into acetate relies on subsequent phosphotransacetylase (PTA) and acetate kinase reactions. However, the genome of M. thermoacetica contains no pta homologous gene. It has been speculated that the moth_0864 and moth_1181 gene products sharing similarities with an evolutionarily distinct phosphotransacylase involved in 1,2-propanediol utilization (PDUL) of Salmonella enterica act as PTAs in M. thermoacetica. Here, we demonstrate specific PTA activities with acetyl-CoA as substrate of 9.05 and 2.03 U/mg for the recombinant enzymes PDUL1 (Moth_1181) and PDUL2 (Moth_0864), respectively. Both showed maximal activity at 65 °C and pH 7.6. Native proteins (90 kDa) are homotetramers composed of four subunits with apparent molecular masses of about 23 kDa. Thus, one or both PDULs of M. thermoacetica might act as PTAs in vivo catalyzing the penultimate step of the Wood-Ljungdahl pathway toward the formation of acetate. In silico analysis underlined that up to now beside of M. thermoacetica, only Sporomusa ovata contains only PDUL like class(III)-PTAs but no other phosphotransacetylases or phosphotransbutyrylases (PTBs).
authors.affiliation: BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK.
authors.forename: Ronja
authors.initials: R
authors.lastname: Breitkopf
authors.affiliation: Abteilung Mikrobiologie, Institut für Biowissenschaften, Universität Rostock, Albert-Einstein-Str. 3, 18059, Rostock, Germany.
authors.forename: Ronny
authors.initials: R
authors.lastname: Uhlig
authors.affiliation: Abteilung Mikrobiologie, Institut für Biowissenschaften, Universität Rostock, Albert-Einstein-Str. 3, 18059, Rostock, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Drenckhan
authors.affiliation: Abteilung Mikrobiologie, Institut für Biowissenschaften, Universität Rostock, Albert-Einstein-Str. 3, 18059, Rostock, Germany. ralf-joerg.fischer@uni-rostock.de.
authors.forename: Ralf-Jörg
authors.identifier: http://orcid.org/0000-0003-0522-3206
authors.initials: RJ
authors.lastname: Fischer
mesh_terms: D000085:Acetates / Q000378:metabolism; D000105:Acetyl Coenzyme A / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D005798:Genes, Bacterial; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D058845:Moorella / Q000201:enzymology* / Q000235:genetics; D010709:Phosphate Acetyltransferase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019946:Propylene Glycol / Q000378:metabolism*; D055503:Protein Multimerization
chemical_list: D000085:Acetates; D001426:Bacterial Proteins; D019946:Propylene Glycol; D000105:Acetyl Coenzyme A; D010709:Phosphate Acetyltransferase
keywords: Moorella thermoacetica; Phosphotransacetylase (PTA); Propanediol utilization protein (PDUL); Wood–Ljungdahl pathway