title: Cytoplasmic and periplasmic proteomic signatures of exponentially growing cells of the psychrophilic bacterium Pseudoalteromonas haloplanktis TAC125.
abstract: The psychrophilic model bacterium Pseudoalteromonas haloplanktis is characterized by remarkably fast growth rates under low-temperature conditions in a range from 5°C to 20°C. In this study the proteome of cellular compartments, the cytoplasm and periplasm, of P. haloplanktis strain TAC125 was analyzed under exponential growth conditions at a permissive temperature of 16°C. By means of two-dimensional protein gel electrophoresis and mass spectrometry, a first inventory of the most abundant cytoplasmic and periplasmic proteins expressed in a peptone-supplemented minimal medium was established. By this approach major enzymes of the amino acid catabolism of this marine bacterium could be functionally deduced. The cytoplasmic proteome showed a predominance of amino acid degradation pathways and tricarboxylic acid (TCA) cycle enzymes but also the protein synthesis machinery. Furthermore, high levels of cold acclimation and oxidative stress proteins could be detected at this moderate growth temperature. The periplasmic proteome was characterized by a significant abundance of transporters, especially of highly expressed putative TonB-dependent receptors. This high capacity for protein synthesis, efficient amino acid utilization, and substrate transport may contribute to the fast growth rates of the copiotrophic bacterium P. haloplanktis in its natural environments.
authors.affiliation: Institute of Marine Biotechnology, W. Rathenau Str. 49a, 17489 Greifswald, Germany.
authors.forename: Boris
authors.initials: B
authors.lastname: Wilmes
authors.forename: Holger
authors.initials: H
authors.lastname: Kock
authors.forename: Susanne
authors.initials: S
authors.lastname: Glagla
authors.forename: Dirk
authors.initials: D
authors.lastname: Albrecht
authors.forename: Birgit
authors.initials: B
authors.lastname: Voigt
authors.forename: Stephanie
authors.initials: S
authors.lastname: Markert
authors.forename: Antje
authors.initials: A
authors.lastname: Gardebrecht
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Bode
authors.forename: Antoine
authors.initials: A
authors.lastname: Danchin
authors.forename: Georges
authors.initials: G
authors.lastname: Feller
authors.forename: Michael
authors.initials: M
authors.lastname: Hecker
authors.forename: Thomas
authors.initials: T
authors.lastname: Schweder
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism; D002952:Citric Acid Cycle; D003470:Culture Media; D003600:Cytosol / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D055873:Extreme Cold; D015870:Gene Expression; D019897:Periplasm / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*; D031161:Pseudoalteromonas / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D020543:Proteome