title: Recombinant E. coli expressing Vitreoscilla haemoglobin prefers aerobic metabolism under microaerobic conditions: a proteome-level study.
abstract: Vitreoscilla haemoglobin (VHb) expression in heterologous host was shown to enhance growth and oxygen utilization capabilities under oxygen-limited conditions. The exact mechanism by which VHb enhances the oxygen utilization under oxygen-limiting conditions is still unknown. In order to understand the role of VHb in promoting oxygen utilization, changes in the total protein profile of E. coli expressing the vgb gene under its native promoter was analysed. Two-dimensional difference gel electrophoresis (2D DIGE) was employed to quantify the differentially expressed proteins under oxygen-limiting conditions. Overexpression of proteins involved in aerobic metabolic pathways and suppression of proteins involved in non-oxidative metabolic pathways shown in this study indicates that the cells expressing VHb prefer aerobic metabolic pathways even under oxygen limitation. Under these conditions, the expression levels of proteins involved in central metabolic pathways, cellular adaptation and cell division were also found to be altered. These results imply that Vitreoscilla haemoglobin expression alters aerobic metabolism specifically, in addition to altering proteins involved in other pathways, the significance of which is not clear as of now.
authors.affiliation: Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai 625 021.
authors.forename: Bini
authors.initials: B
authors.lastname: Ramachandran
authors.forename: Kanak Lata
authors.initials: KL
authors.lastname: Dikshit
authors.forename: Kuppamuthu
authors.initials: K
authors.lastname: Dharmalingam
mesh_terms: D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D019069:Cell Respiration / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006420:Hemeproteins / Q000096:biosynthesis*; D010100:Oxygen / Q000378:metabolism; D020543:Proteome / Q000235:genetics; D054793:Truncated Hemoglobins / Q000096:biosynthesis* / Q000235:genetics; D020589:Vitreoscilla / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006420:Hemeproteins; D020543:Proteome; D054793:Truncated Hemoglobins; C100771:Vgb protein, Bacteria; C082613:hemoglobin protein, Vitreoscilla; D010100:Oxygen