RNA polymerase III transcription complexes on chromosomal 5S rRNA genes in vivo: TFIIIB occupancy and promoter opening.
Quantitative analysis of multiple-hit potassium permanganate (KMnO(4)) footprinting has been carried out in vivo on Saccharomyces cerevisiae 5S rRNA genes. The results fix the number of open complexes at steady state in exponentially growing cells at between 8 and 17% of the 150 to 200 chromosomal copies. UV and dimethyl sulfate footprinting set the transcription factor TFIIIB occupancy at 23 to 47%. The comparison between the two values suggests that RNA polymerase III binding or promoter opening is the rate-limiting step in 5S rRNA transcription in vivo. Inhibition of RNA elongation in vivo by cordycepin confirms this result. An experimental system that is capable of providing information on the mechanistic steps involved in regulatory events in S. cerevisiae cells has been established.
Costanzo
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G
Istituto Pasteur-Fondazione Cenci Bolognetti, c/o Dipartimento di Genetica e Biologia Molecolare, Università di Roma, La Sapienza, Rome, Italy.
Camier
S
S
Carlucci
P
P
Burderi
L
L
Negri
R
R
D001483:Base Sequence; D015825:Chromosomes, Fungal; D018983:DNA Footprinting / Q000379:methods; D004271:DNA, Fungal; D003838:Deoxyadenine Nucleotides / Q000494:pharmacology; D008969:Molecular Sequence Data; D011196:Potassium Permanganate / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D012320:RNA Polymerase III / Q000235:genetics*; D012331:RNA, Fungal; D012341:RNA, Ribosomal, 5S / Q000187:drug effects / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D013463:Sulfuric Acid Esters; D035361:Transcription Factor TFIIIB; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014466:Ultraviolet Rays
D004271:DNA, Fungal; D003838:Deoxyadenine Nucleotides; D012331:RNA, Fungal; D012341:RNA, Ribosomal, 5S; D013463:Sulfuric Acid Esters; D035361:Transcription Factor TFIIIB; D014157:Transcription Factors; D011196:Potassium Permanganate; C011746:3'-deoxyadenosine 5'-triphosphate; D012320:RNA Polymerase III; C007482:dimethyl sulfate