THE C-TERMINAL DOMAIN REVEALED IN THE STRUCTURE OF RNA-POLYMERASE-II

The location of the CTD in the structure of RNA polymerase II has been determined by electron crystallography at 16 Angstrom resolution. Dif ference maps between wild-type enzyme and that lacking the CTD, or wit h an antibody fragment bound in place of the CTD, disclose the site of attachment of the CTD to the polymerase. Appropriate display of the p olymerase structure reveals the CTD as an element projecting from this site of attachment into solution. A low relative density and large vo lume of this element identify the CTD as a conformationally mobile reg ion. (C) 1996 Academic Press Limited