Це відео не доступне.
Перепрошуємо.
SOS repair of DNA II DNA repair
Вставка
- Опубліковано 12 лис 2019
- The SOS response is a global response to DNA damage in which the cell cycle is arrested and DNA repair and mutagenesis is induced. The system involves the RecA protein.
During normal growth, the SOS genes are negatively regulated by LexA repressor protein dimers. Under normal conditions, LexA binds to a 20-bp consensus sequence (the SOS box) in the operator region for those genes. Some of these SOS genes are expressed at certain levels even in the repressed state, according to the affinity of LexA for their SOS box.
Activation of the SOS genes occurs after DNA damage by the accumulation of single stranded (ssDNA) regions generated at replication forks, where DNA polymerase is blocked. RecA forms a filament around these ssDNA regions in an ATP-dependent fashion, and becomes activated. The activated form of RecA interacts with the LexA repressor to facilitate the LexA repressor's self-cleavage from the operator
Once the pool of LexA decreases, repression of the SOS genes goes down according to the level of LexA affinity for the SOS boxes. Operators that bind LexA weakly are the first to be fully expressed. In this way LexA can sequentially activate different mechanisms of repair. Genes having a weak SOSbox (such as lexA, recA, uvrA, uvrB, and uvrD) are fully induced in response to even weak SOS-inducing treatments. Thus the first SOS repair mechanism to be induced is nucleotide excision repair (NER), whose aim is to fix DNA damage without commitment to a full-fledged SOS response. If, however, NER does not suffice to fix the damage, the LexA concentration is further reduced, so the expression of genes with stronger LexA boxes (such as sulA, umuD, umuC - these are expressed late) is induced. SulA stops cell division by binding to FtsZ, the initiating protein in this process. This causes filamentation, and the induction of UmuDC-dependent mutagenic repair. As a result of these properties, some genes may be partially induced in response to even endogenous levels of DNA damage, while other genes appear to be induced only when high or persistent DNA damage is present in the cell.
You see, she could explain something in two minutes which my lector couldn't explain for an hour.
Thankyou dear
Helped me in my exam... Thank you for explaining in simple words
Happy to help 😃
You really simplified the basic mechanism. Love the representation
😊😊😊
Thank you so much for the video
It's my pleasure
Thank you so much 👍❤️😀 really helpful
Welcome and all the best 😊
Thanks for explaning in less than 2 minutes. Very easy to follow thank you ^^
Welcome. So glad it was useful to you ☺️
I thought this topic is quite difficult but u explained it in a minute 😶😌😌👍
Thankyou. It's nice to know that it was helpful to you
Great analysis
thanks :)
Thank you so much ❤
Happy to help ☺️
Tysm ... Yaar
hoping it will be helpful :)
I'm loving your UA-cam videos......it is easy to remember 💝
That's great. Happy to help. Do share the videos and keep learning 🙂😉
Very memorable and cute. Nice work :)
Thank you. Happy to help 😊😊😊
very nice, to the point explanation !!
Thank you. Happy to help 😊
Continue please..
awesome
Thanks 👍😊
Do share 😇
Ok
😊
Thank you so much ❤️
Happy to help 😊
Thank you ❤️❤️
Welcome 😄
Hey, you got a new subscriber😙
Thankyou
Like magic✨, thanks
Thankyou ☺️
Super
Thankyou
Thank u 😊
Welcome 😄
thanks alot ..perfect
Add recombination repair video too!
Haa bhai udya exam ahe....tuzya sathi lagech ny banavnar video😂 Anisha Here from other mobile broo😎
lol. sorry
Im hoping your exam went well
@@sadramkamble5122 😂
@@BioMagica yes I scored well!
Awesome
Thankyou 😊
I have a exam tomorrow. This helps me so well n instantly
That's great to know. All the best to you. Study smart. Don't stress. 😇☺️
Helpful
Glad to help. Please do share :)
😍😍😍
:)
❤❤❤
Is it for prokaryotes or Eukaryotes ??
Prokaryotes