title: The studies of cooperative regions in T7 RNA polymerase.
abstract: The heat denaturation of bacteriophage T7 RNA polymerase (T7RNAP) was studied by scanning microcalorimetry. The thermodynamic parameters of the denaturation were estimated within the pH range 6-9. The analysis of the denaturation curves showed the presence of two cooperative parts of the T7RNAP molecule melting according to the 'all-or-none' principle. The molecular masses of these parts were determined as 22 and 77 kDa. These values are close to the molecular masses of protein domains obtained from X-ray diffraction and limited trypsinolysis data. The smaller N-terminal domain was shown to increase the thermostability of the 'catalytic' C-terminal domain within the intact T7RNAP molecule.
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow.
authors.forename: I I
authors.initials: II
authors.lastname: Protasevich
authors.forename: L V
authors.initials: LV
authors.lastname: Memelova
authors.forename: S N
authors.initials: SN
authors.lastname: Kochetkov
authors.forename: A A
authors.initials: AA
authors.lastname: Makarov
mesh_terms: D017123:Bacteriophage T7 / Q000201:enzymology; D002152:Calorimetry, Differential Scanning; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry*; D011487:Protein Conformation; D011489:Protein Denaturation; D013816:Thermodynamics; D014764:Viral Proteins
chemical_list: D014764:Viral Proteins; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases