Arabidopsis thaliana contains two genes for TFIID

Abstract

The general transcription initiation factor TFIID plays a primary part in the activation of eukaryotic genes transcribed by RNA polymerase II. Binding of TFIID to the TATA box initiates the assembly of other general transcription factors as well as RNA polymerase II at the promoter resulting in a preinitiation complex capable of accurate transcription initiation in vitro. Human TFIID has been shown to interact with various regulatory factors. The observation that stimulation of transcription by different trans-acting factors is mediated through distinct TATA elements led to the suggestion that different types of TFIID may exist in yeast, humans and plants. Here we report the cloning and characterization of two distinct TFIID complementary DNA clones from Arabidopsis thaliana. Furthermore, we have found that TFIID from Arabidopsis and other organisms shows homology to helix-loop-helix proteins.

TRF2: TRansForming the view of general transcription factors

“…[29][30][31] Using low-stringency hybridization, 2 distinct TBPs were identified in Arabidopsis thaliana and then in maize. 43,44 Since then, 3 TBP-related factors (TRFs; TRF1, TRF2 and TRF3) have been discovered in the animal kingdom based on their homology to the C-terminal core domain of TBP (for a review see refs. [45][46][47][48][49].…”

Two different cDNAs encoding TFIID proteins of maize

“…Both factors are able to confer basal transcription but exhibit a different binding pattern in electrophoretic mobility shift assays [25]. We report here the isolation and characterization of two different types of cDNA clones from a maize leaf cDNA library encoding TATA box binding proteins.…”

“…The proteins derived from the longest open reading frames of the different cDNAs reveal the highly conserved structural motifs common to the C-terminal region of TFIID and display a N-terminal domain which is different from the TFIID clones of other organisms analysed so far. A maize leaf cDNA library in lambda ZAP (Stratagene) was screened with u 538 bp HindlI/EcoRI fragment of the TFIID cDNA AT1 from Arubidopsis rhuhrta [25] by standard procedures [26]. Hybridization with the DIG-labeled probes (Boehringer) was performed at 42°C for at least I6 h in a buffer containing 5x SW, 20% fonnamide, 0.1% sarcosyl, 0.02% SDS and 2% blocking powder (Boehringer) followed by washes at 65°C for 15 min each in 2x SW, 0.1% SDS and 0.…”

Multimerization of the mouse TATA-binding protein (TBP) driven by its C-terminal conserved domain

“…Actually, the affinity between TBP and TATA-box DNA is known to be very high (Kd = 2 -4 x 10-9 M) (41). Alternatively, TBP may utilize the helixloop-helix (HLH) motif kown as a structure for protein-protein interaction, since TBP is thought to contain a HLH motif in the C-terminal domain (40 (24,25).…”

“…We found that the C-terminus of TBP was essential for TBP-TBP interaction. The C-terminal domain of TBP has multiple motifs/domains for DNA binding (basic repeat, direct repeat and sigma homology) (38)(39)(40). X-ray crystallography has shown that TBP forms a saddle shape structure (23).…”