gene regulation- Lac operon(락 오페론)

소개

Lac operon에 관한 발표내용입니다.
Lac operon의 핵심내용과 메카니즘을 애니메이션으로 나타내었고, X-gal과 cAMP, CAP(catabolite activator protein), repressor의 작용 메카니즘, negative gene regulation, positive gene regulation에 대해서, 그리고 beta galactosidase의 구조와 alpha complementation의 원리에 대해서 충분한 schimetic diagram을 포함해서 완벽에 가깝게 정말 고생해서 정리하였습니다. subcloning competence cell(strain)으로 DH5-alpha와 plasmid로는 pUC19에 대해서도 자세하게 정리되어있으며 x-gal에서의 white/blue colony screening에 대해서까지 이론과 실험에 대한 완전한 내용이 들어있습니다.
거의 완벽에 가깝게 정리했습니다.

목차

Overview of Lac operon
Negative and Positive control
cAMP&CAP
The Effects of IPTG Concentration
How does it work?
The strain, DH5α of the Competent Cell
Features of Plasmid pUC19
Alpha complementation
Screening of white & blue colony on x-gal
Materials & apparatus
Proceture
References

본문내용

The Lac Operon
Genes in the lac operon allow E. coli bacteria to metabolize lactose
Lactose is a sugar that E. coli is unlikely to encounter, so it would be wasteful to produce the proteins needed to metabolize it unless necessary
Metabolizing lactose for energy only makes sense when two criteria are met:
Other more readily metabolized sugar (glucose) is unavailable
Lactose is available
The lac operon is made up of a control region and four genes
The four genes are:
LacZ - b-galactosidase - An enzyme that hydrolizes the bond between galactose and glucose
LacY - Codes for a permease that lets lactose across the cell membrane
LacA - Transacetylase - An enzyme whose function in lactose metabolism is uncertain
Repressor - A protien that works with the control region to control expression of the operon
The control region is made up of two parts:
Promoter (Lac P)
These are specific DNA sequences to which RNA Polymerase binds so that transcription can occur
The lac operon promoter also has a binding site for another protein called CAP
Operator (Lac O)
The binding site of the repressor protein
The operator is located down stream (in the 3’ direction) from the promoter so that if repressor is bound RNA Polymerase can’t transcribe

참고자료

· http://en.wikipedia.org/wiki/Lac_operon
· http://www.biodynamics.co.jp/images/prd_ds210/ds222.pdf
· http://blog.naver.com/wandjina1
· http://www4.nau.edu/biology/bio350/lecture%205%20350%20fall%2006.ppt
· http://www.life.umd.edu/grad/MLfsc/res/RecombomamtDNA&Medicine.ppt