transcription factors - (Dec/25/2006 )

Hi,
I just wanted to now what brings in the sequence specificity of transcription factors. How does a transcription factor or any DNA/RNA binding protein know which sequence to bind to??I know that TFs bind to certain specified seuqences...why do they bind to these and not other sequences?

hi

transcription factors are one group of what is called "DNA-binding protiens"...these factors bind either directly to a DNA sequence (promoter), or may bind to factors already bound to that sequence...they have a DNA- binding sites ..just like restriction enzymes i thought

well, each different sequence will have a specific 3-dimensional structure, right? minor variations based on the exact base alignment...so the TF will recognize the specific structure and bind there

go to google.com, select the image tab, and look up some transcription factors...you will find digital models of TFs bound to DNA that make it easier to visualize what is happening