KDC shows Divergent evolution, in which the genes for an enzyme with one substrate specificity give rise, during evolution, to closely related enzymes with different substrate specificities but the same enzymatic mechanism.

TLS Online TPP Program

#Id: 618

#Unit 2. Cellular Organization

Attenuator riboswitch (Leader sequence) region 1 is translated  till UGA (R1-2) in case of high trp concentration

TLS Online TPP Program

#Id: 619

#Unit 2. Cellular Organization

Region 1 Leader peptide is of 14 Amino acids Met------Ser

TLS Online TPP Program

#Id: 620

#Unit 2. Cellular Organization

At high or low trp concentration, RNA Polymerase synthesizes full mRNA till region 4

TLS Online TPP Program

#Id: 621

#Unit 2. Cellular Organization

Attenuator riboswitch (Leader sequence) region 1 is translated  till UGA (R1-2) at high trp concentration due to two conditions

1. Ribosome quickly crosses codon 10, 11

2. After crossing codon 10, 11 ribosome prematurely terminated at UGA at the end of Region 1

TLS Online TPP Program

#Id: 622

#Unit 2. Cellular Organization

During Attenuation, Region 3-4 forms hairpin then second hairpin is formed between Region 1-2

TLS Online TPP Program

#Id: 623

#Unit 2. Cellular Organization

Dual hairpin formation take place due to ribosome fall from UGA