04 June 2021
Vol 372, Issue 6546

About The Cover

Cover image expansion

COVER The human transcription preinitiation complex (PIC; pink and red) and multisubunit Mediator complex (orange, left) are assembled into a supercomplex (76 polypeptides, molecular mass: 4.1 megadaltons) on a promoter region of DNA (orange coil, center) to initiate gene transcription. Mediator binds RNA polymerase II (purple) in the PIC and stimulates phosphorylation of its C-terminal domain (highlighted in white), a critical event in transcription initiation. See page eabg0635.
Illustration: V. Altounian/Science; Data: Y. Xu/Fudan University