联系方式:400-990-3999 / 邮箱:sales@xiyashiji.com
西亚试剂 —— 品质可靠,值得信赖
Structural Basis of Transcription Initiation
Yu Zhang1, Yu Feng1, Sujoy Chatterjee1, Steve Tuske2, Mary X. Ho2, Eddy Arnold2, Richard H. Ebright1,*
During transcription initiation, RNA polymerase (RNAP) binds and unwinds promoter DNA to form an RNAP-promoter open complex. We have determined crystal structures at 2.9 and 3.0 Å resolution of functional transcription initiation complexes comprising Thermus thermophilus RNA polymerase, σA, and a promoter DNA fragment corresponding to the transcription bubble and downstream dsDNA of the RNAP-promoter open complex. The structures show that σ recognizes the –10 element and discriminator element through interactions that include the unstacking and insertion into pockets of three DNA bases, and that RNAP recognizes the –4/+2 region through interactions that include the unstacking and insertion into a pocket of the +2 base. The structures further show that interactions between σ and template-strand ssDNA preorganize template-strand ssDNA to engage the RNAP active center.