The TATA binding protein is essential for the initiation of transcription. It formas a central part of the "pre-initiation complex". It binds to the TATA box found in the promoters of many eukaryotic genes transcribed by RNA polymerase II. (Most mRNA precursors.) The 'saddle" shaped protein does not sit over the DNA in the groove, as had been predicted. Instead, it forces the DNA to bend up and around the inside of the saddle. This forces the minor grooves to open slightly. The protein is a monomer, consisting of approximately 200 amino acids, folded into 2 similar domains. The recognition is primarily due to the shape of the underside of the saddle, which fits perfectly into the minor groove. The protein is held in place by many weak non-specific interactions (which is highly unusual but may account for the fact that the TATA binding protein can interact with many different promoter sequences). "Binding" causes some local unwinding of the B-DNA, and it is this which causes the opening of the groove, together with the 80o bend in the DNA. The bending is caused by the insertion of 4 phenylalanine sidechains (coloured cyan here) in between the bases. This wedges open the DNA, causing a large bend. The pairs of Now you know something about DNA binding proteins, the only thing left to learn about is the denaturing and reannealing of DNA strands. To go straight to the last tutorial, press NEXT, or alternatively, go HOME.
The 'saddle" shaped protein does not sit over the DNA in the groove, as had been predicted. Instead, it forces the DNA to bend up and around the inside of the saddle. This forces the minor grooves to open slightly. The protein is a monomer, consisting of approximately 200 amino acids, folded into 2 similar domains. The recognition is primarily due to the shape of the underside of the saddle, which fits perfectly into the minor groove. The protein is held in place by many weak non-specific interactions (which is highly unusual but may account for the fact that the TATA binding protein can interact with many different promoter sequences). "Binding" causes some local unwinding of the B-DNA, and it is this which causes the opening of the groove, together with the 80o bend in the DNA. The bending is caused by the insertion of 4 phenylalanine sidechains (coloured cyan here) in between the bases. This wedges open the DNA, causing a large bend. The pairs of Now you know something about DNA binding proteins, the only thing left to learn about is the denaturing and reannealing of DNA strands. To go straight to the last tutorial, press NEXT, or alternatively, go HOME.
The protein is a monomer, consisting of approximately 200 amino acids, folded into 2 similar domains. The recognition is primarily due to the shape of the underside of the saddle, which fits perfectly into the minor groove.
The protein is held in place by many weak non-specific interactions (which is highly unusual but may account for the fact that the TATA binding protein can interact with many different promoter sequences). "Binding" causes some local unwinding of the B-DNA, and it is this which causes the opening of the groove, together with the 80o bend in the DNA.
The bending is caused by the insertion of 4 phenylalanine sidechains (coloured cyan here) in between the bases. This wedges open the DNA, causing a large bend. The pairs of Now you know something about DNA binding proteins, the only thing left to learn about is the denaturing and reannealing of DNA strands. To go straight to the last tutorial, press NEXT, or alternatively, go HOME.
Now you know something about DNA binding proteins, the only thing left to learn about is the denaturing and reannealing of DNA strands. To go straight to the last tutorial, press NEXT, or alternatively, go HOME.
