Core E的结构与功能EnzymeMovementDNA coding strand(βUnwinding point(aRewinding point (α)10-17bpH解链区DNA template strandRNA binding site(β)RNA/DNAhybrid（β）
DNA coding strand (β’ ) Unwinding point (α) RNA/DNA hybrid (β) 10-17bp 解链区 RNA binding site(β) DNA template strand Rewinding point (α) Enzyme Movement
CoreE的结构与功能Enzyme MovementDNAcodingstrand(βUnwinding point (aRewindingpoint（a）10-17bp解链区DNAtemplate strandERNAbinding site(β)RNADNAhybrid（）专一性地结合ATPorGTPI site (Rif s) ;非专一性结合NTPE site (Rif R) ;
DNA coding strand (β’ ) Unwinding point (α) RNA/DNA hybrid (β) 10-17bp 解链区 RNA binding site(β) DNA template strand Rewinding point (α) Enzyme Movement I site (Rif S ) ; E site (Rif R ) ; 非专一性结合NTP 专一性地结合ATP or GTP I E
locatethe determinationofRifampinresistancePurificationoftheindividualsubunitsofE.coliRNApolymeraseinUreaelectrophoresisbuffer(Alfredheil&Ziling1970)Separationand reconstitutionof RNA polymerase
Separation and reconstitution of RNA polymerase Purification of the individual subunits of E.coli RNA polymerase in Urea electrophoresis buffer (Alfred heil & Ziling 1970) locate the determination of Rifampin resistance
Reconstitution of RNApolRif sSeparateRif RRifampicin-sensitiveReconstituteRifampicin-resistantSeparateThe β subunit is obviouslyRifampicin-resistantdeterminant of Rifs or RifRRifR
Reconstitution of RNApol. The β subunit is obviously determinant of Rif S or Rif R Rif S Rif R Rif R
Rifampin对RNApol的抑制表现Isite的竞争Rif与ATP/GTP对当Rif紧密与β亚基结合Isite的填充→阻止ATPIGTP对当l,Esite被pppXpYpZ(3Nts）填充Rif失去抑制效应Rifampin是RNA合成起始的抑制剂
Rifampin对RNApol 的抑制表现 当 I, E site被 pppXpYpZ(3Nts) 填充 Rif失去抑制效应 Rifampin是RNA合成起始的抑制剂 • Rif 与ATP / GTP对 I site的竞争 当Rif紧密与β亚基结合 → 阻止ATP/GTP对 I site 的填充