Regional codon randomization: defining a TATA-binding protein surface required for RNA polymerase III transcription.
The TATA-binding protein (TBP) is required for transcription by all three nuclear RNA polymerases. TBP was subjected to regional codon randomization, a codon-based mutagenesis method that generates complex yet compact protein libraries. Analysis of 186 temperature-sensitive TBP mutants yielded 65 specifically defective in transcription by RNA polymerase III (Pol III). These mutants map to a limited TBP surface that may interact with Tds4, a component of the Pol III transcription factor TFIIIB. Strains that contain the Pol III-defective derivatives have increased amounts of messenger RNA, which suggests that competition among TBP-interacting factors for limiting quantities of TBP determines the ratio of Pol II and Pol III transcription in vivo.
Cormack
B P
BP
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.
Struhl
K
K
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D003062:Codon; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D012320:RNA Polymerase III / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics; D011897:Random Allocation; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016385:TATA Box; D035181:TATA-Box Binding Protein; D013696:Temperature; D035361:Transcription Factor TFIIIB; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D003062:Codon; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D035181:TATA-Box Binding Protein; D035361:Transcription Factor TFIIIB; D014157:Transcription Factors; D012343:RNA, Transfer; D012320:RNA Polymerase III