TY - JOUR
T1 - Spatial arrangement of δ-factor and core enzyme of Escherichia coli RNA polymerase. A neutron solution scattering study
AU - Lederer, H.
AU - Mortensen, K.
AU - May, R.P.
AU - Baer, G.
AU - Crespi, H.L.
AU - Dersch, D.
AU - Heumann, H.
PY - 1991
Y1 - 1991
N2 - By means of neutron solution scattering we determined the position and orientation of core enzyme and σ-factor within the Escherichia coli RNA polymerase holoenzyme with the aim of improving existing models. The individual components, core enzyme (E) and σ-factor (σ), were highlighted by deuterium labeling and their center-to-center distances determined in the monomeric and the dimeric holoenzyme. The following distance parameters were obtained: dE1 − σ1 = 8.6(± 1) nm, dE1 − E2 = 11.5(± 1) nm, dσ1 − σ2 = 12.0(±0.7) nm, dE1 − σ2 = 9(± 3) nm. Using a triangulation procedure the position of the σ-factors, σ1 and σ2, were determined with respect to the mass center of the core enzyme molecules, E1 and E2 assuming a symmetrical arrangement of the holoenzyme molecules in the dimer (C2 symmetry). In addition, the orientation of the σ-factor with respect to core enzyme was estimated by means of model calculations. The obtained model of holoenzyme depicts the σ-factor as buried in a groove of core enzyme, probably between the large subunits β′ and β.
AB - By means of neutron solution scattering we determined the position and orientation of core enzyme and σ-factor within the Escherichia coli RNA polymerase holoenzyme with the aim of improving existing models. The individual components, core enzyme (E) and σ-factor (σ), were highlighted by deuterium labeling and their center-to-center distances determined in the monomeric and the dimeric holoenzyme. The following distance parameters were obtained: dE1 − σ1 = 8.6(± 1) nm, dE1 − E2 = 11.5(± 1) nm, dσ1 − σ2 = 12.0(±0.7) nm, dE1 − σ2 = 9(± 3) nm. Using a triangulation procedure the position of the σ-factors, σ1 and σ2, were determined with respect to the mass center of the core enzyme molecules, E1 and E2 assuming a symmetrical arrangement of the holoenzyme molecules in the dimer (C2 symmetry). In addition, the orientation of the σ-factor with respect to core enzyme was estimated by means of model calculations. The obtained model of holoenzyme depicts the σ-factor as buried in a groove of core enzyme, probably between the large subunits β′ and β.
KW - Materialers atomare struktur og egenskaber
U2 - 10.1016/0022-2836(91)90669-W
DO - 10.1016/0022-2836(91)90669-W
M3 - Journal article
SN - 0022-2836
VL - 219
SP - 747
EP - 755
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 4
ER -