title: The translation initiation factor, PeIF5B, from Pisum sativum displays chaperone activity.
abstract: We earlier documented the structural and functional characterization of PeIF5B factor from Pisum sativum that shows strong homology to the universal translation initiation factor eIF5B (Rasheedi et al., 2007, 2010 [12,13]). We now show that PeIF5B is an unusually thermo-stable protein resisting temperatures up to 95 °C. PeIF5B prevents thermal aggregation of heat labile proteins, such as citrate synthase (CS) and NdeI, under heat stress or chemical denaturation conditions and promotes their functional folding. It also prevents the aggregation of DTT induced insulin reduction. GTP appears to stimulate PeIF5B-mediated chaperone activity. In-vivo, PeIF5B over expression significantly enhances, the viability of Escherichia coli cells after heat stress (50 °C). These observations lead us to conclude that PeIF5B, in addition to its role in protein translation, has chaperone like activity and could be likely involved in protein folding and protection from stress.
authors.affiliation: Molecular Biology Unit, National Institute of Nutrition, Hyderabad 500 007, India.
authors.forename: Madhuri
authors.initials: M
authors.lastname: Suragani
authors.forename: Sheeba
authors.initials: S
authors.lastname: Rasheedi
authors.forename: Seyed E
authors.initials: SE
authors.lastname: Hasnain
authors.forename: Nasreen Z
authors.initials: NZ
authors.lastname: Ehtesham
mesh_terms: D004926:Escherichia coli; D040061:Eukaryotic Initiation Factor-5 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D018869:Heat-Shock Response; D006358:Hot Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D007328:Insulin / Q000737:chemistry; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D018532:Pisum sativum / Q000378:metabolism*; D010442:Peptide Chain Initiation, Translational; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017510:Protein Folding; D055550:Protein Stability
chemical_list: D040061:Eukaryotic Initiation Factor-5; D007328:Insulin; D018832:Molecular Chaperones; D010940:Plant Proteins; D006160:Guanosine Triphosphate