Active JAK kinase phosphorylates several tyrosine residues in the receptor’s cytosolic domain and activates a STAT transcription factor that moves directly to the nucleus

TLS Online TPP Program

#Id: 6110

#Unit 3. Fundamental Processes

There are 3 cellular ways to treat mutations on DNA

Repair- Most common

Reversal- Most expensive and rare

Bypass – Last resort and carry mutation without correction

TLS Online TPP Program

#Id: 6111

#Unit 3. Fundamental Processes

Genes whose products are involved in controlling the fidelity of DNA synthesis during either replication or repair may be identified by mutations that have a mutator phenotype called as mut system of repair or MMR

TLS Online TPP Program

#Id: 6112

#Unit 3. Fundamental Processes

Mismatch Repair removes errors that escape Proofreading

TLS Online TPP Program

#Id: 6113

#Unit 3. Fundamental Processes

In Escherichia coli, MutS scans the DNA, recognizing mismatches from the distortion they cause in the DNA backbone. 

MutS has an ATPase activity that is required for mismatch repair and recruits MutL, a second protein component of the repair system. MutL, in turn, activates MutH, an enzyme that causes an incision or nick on one strand near the site of the mismatch. Nicking is followed by the action of a specific helicase (UvrD) helicase unwinds the DNA, starting from the incision and moving in the direction of the site of the mismatch, and the filled in by DNA polymerase III

TLS Online TPP Program

#Id: 6114

#Unit 3. Fundamental Processes

MutH protein binds at hemimethylated daughter strands created by dam methylase

TLS Online TPP Program

#Id: 6115

#Unit 3. Fundamental Processes