KOAZK rule - what is it??? (May/07/2007 )
hi everybody
does anybody know about KOZAK rule??? something about promoter. i googled it and also search in some books find i dont get much informatin about this, if you are familier with this could please help me providing some information???
Here are some link, not full but give you some basic ideas:
http://en.wikipedia.org/wiki/Kozak_sequence
http://en.wikipedia.org/wiki/Kozak_consensus_sequence
The Kozak sequence is named after Marilyn Kozak. The sequence is contiguous with the ATG start codon and greatly increases the efficiency of translation and overall expression of the product gene. In eukaryotic translation, 40S ribosomal subunits binds to the 5' end mRNA and scan it from 5' to 3' until they reach AUG initiation codon. Usually the first AUG is the initiation but not always. This AUG is not able to slow the migration of the 40S subunit by itself. Only when AUG is found in the right context (Kozak sequence) then it is recognized and works efficiently as the initiation codon for translation. The Kozak sequence slows down the ribosomal scanning and improve the chance of it recognising the start of translation at the AUG start codon. The working sequence could be NNNPuNNAUGG. Pu is purine base (A or G) and N is any nucleotide THe key residues of it are the bases at positions -4 and +1 (Pu and the G immediately following AUG). These bases can increase the efficiency of translation by 10 fold. For the AUG that could be found before the real starting codon, normally the ribosome will pass it by (no Kozak sequence, so no stop). Or sometimes it will read, but the reading (translation) will be terminate when it reaches the real AUG (in Kozak sequence). This works for most cases, except maybe the IRES
does anybody know about KOZAK rule??? something about promoter. i googled it and also search in some books find i dont get much informatin about this, if you are familier with this could please help me providing some information???
check pubmed for Kozak and start from the last page. You can find the abstracts over a period of time where the Kozak sequence is also mentioned.
PI suggests C ATG G, my old PI suggested CCACC AUG G.
Isnt it Kozak sequence similar to Shine Dalgarno sequence? Just a question 
no its not same
Shine Dalgarno sequence is the ribosomal binding site for bacteria. Kozak is for eukaryotic. The purpose seems to be similar, both to help initating translation by aligning ribosome with the starting codon. Action may be different.
http://en.wikipedia.org/wiki/Shine-Dalgarno_sequence
i searched in pubmed and got a lot of paper of Mr. kozak 
but no full text file of the nature publication