title: Studies on polypeptide-chain-elongation factors from an extreme thermophile, Thermus thermophilus HB8. 1. Purification and some properties of the purified factors.
abstract: Polypeptide chain elongation factors have been purified from an extreme thermophile, Thermus thermophilus HB8. By chromatography on a DEAE-Sephadex column, the factors were separated into two peaks; peak I contained a complex of EF-Tu and EF-Ts, while peak II was composed of EF-Tu.gdp and EF-G. These factors were subsequently purified to homogeneous states and crystallized. The EF-Tu . EF-Ts complex could be resolved into EF-Tu and EF-Ts by chromatography on a Sephadex G-200 column in the presence of 8 M guanidine-HCl. The complex could be reconstituted from EF-Tu and the renatured EF-Ts. No immunological cross-reaction was detected between EF-Tu, EF-Ts, and EF-G from T. thermophilus and the antibodies to their corresponding Escherichia coli factors. The molecular weight of EF-Tu . GDP determined by sedimentation equilibrium and sodium dodecylsulfate/polyacrylamide gel electrophoresis was 49000 and 51000 respectively. On the other hand, the molecular weight of EF-Ts was estimated as 27000 and 64000, respectively, by sodium dodecylsulfate/polyacrylamide gel electrophoresis and Sephadex gel filtration, suggesting that the protein existed probably as a dimer. The molecular weight of the EF-Tu . EF-Ts complex determined by sedimentation equilibrium and by gel filtration, was 142000 and 220000, respectively. Since the molar ratio of EF-Tu to EF-Ts in the EF-Tu . EF-Ts complex was one to one, it was suggested that the complex was composed of 2 mol each of EF-Tu and EF-Ts. The molecular weight of EF-G was estimated as 85000, 80000 and 78000 by equilibrium centrifugation, gel filtration, and sodium dodecylsulfate/polyacrylamide gel electrophoresis respectively.
mesh_terms: D003460:Crystallization; D008722:Methods; D008970:Molecular Weight; D010445:Peptide Elongation Factors / Q000276:immunology / Q000302:isolation & purification*; D011487:Protein Conformation; D013824:Thermus / Q000378:metabolism*
chemical_list: D010445:Peptide Elongation Factors