Structure of theEscherichia coliRNA polymerase α subunit C-terminal domain

Samuel Lara-González, Jens J. Birktoft, Catherine L. Lawson
2010 Acta Crystallographica Section D: Biological Crystallography  
The α subunit C-terminal domain (αCTD) of RNA polymerase (RNAP) is a key element in transcription activation inEscherichia coli, possessing determinants responsible for the interaction of RNAP with DNA and with transcription factors. Here, the crystal structure ofE. coliαCTD (α subunit residues 245–329) determined to 2.0 Å resolution is reported. Crystals were obtained after reductive methylation of the recombinantly expressed domain. The crystals belonged to space groupP21and possessed both
more » ... udo-translational symmetry and pseudo-merohedral twinning. The refined coordinate model (Rfactor = 0.193,Rfree= 0.236) has improved geometry compared with prior lower resolution determinations of the αCTD structure [Jeonet al.(1995),Science,270, 1495–1497; Benoffet al.(2002),Science,297, 1562–1566]. An extensive dimerization interface formed primarily by N- and C-terminal residues is also observed. The new coordinates will facilitate the improved modeling of αCTD-containing multi-component complexes visualized at lower resolution using X-ray crystallography and electron-microscopy reconstruction.
doi:10.1107/s0907444910018470 pmid:20606261 pmcid:PMC2897699 fatcat:t2doshpmejelfnzfzyhog2ggve