Orientation of the transcription preinitiation complex in Archaea

Orientation of the transcription preinitiation complex in Archaea

^*The Wellcome Trust and Cancer Research Campaign Institute of Cancer and Developmental Biology, Tennis Court Road, Cambridge, CB2 1QR, United Kingdom; and ^†Department of Molecular Biophysics and Biochemistry and the ^§Howard Hughes Medical Institute, Yale University, 260 Whitney Avenue/JWG423, P.O. Box 208114, New Haven, CT 06520-8114

Contributed by Paul B. Sigler

Abstract

The basal transcription machinery of Archaea corresponds to the minimal subset of factors required for RNA polymerase II transcription in eukaryotes. Using just two factors, Archaea recruit the RNA polymerase to promoters and define the direction of transcription. Notably, the principal determinant for the orientation of transcription is not the recognition of the TATA box by the TATA-box-binding protein. Instead, transcriptional polarity is governed by the interaction of the archaeal TFIIB homologue with a conserved motif immediately upstream of the TATA box. This interaction yields an archaeal preinitiation complex with the same orientation as the analogous eukaryal complex.

Footnotes

↵ ‡ Present address: Harvard University School of Medicine, Department of Biological Chemistry and Molecular Pharmacology, Boston, MA 02115.
↵ ¶ To whom reprint requests should be addressed. E-mail: spj13{at}mole.bio.cam.ac.uk.
Abbreviations:

RNAP,

RNA polymerase;

TBP,

TATA-box-binding protein;

aTBP and eTBP,

archaeal and eukaryal TBPs;

TFBc,

C-terminal core domain of TFB;

TAF,

TBP-associated factor;

BRE,

TFB-responsive element;

EMSA,

electrophoretic mobility-shift assay