lacZ encodes for b-galactosidase, a tetramer of 500 kD. The enzyme breaks lactose is cleaved into glucose and galactose. This enzyme also produces an important byproduct, b-1,6-allolactase.

TLS Online TPP Program

#Id: 6407

#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: 6408

#Unit 2. Cellular Organization

Dual hairpin formation take place due to ribosome fall from UGA

TLS Online TPP Program

#Id: 6409

#Unit 2. Cellular Organization

Dual hairpin formation (Region 3-4 forms hairpin then second hairpin is formed between Region 1-2) release RNA-DNA hybrid and RNA Polymerase causes seizing transcription of trp operon at high trp concentration.

TLS Online TPP Program

#Id: 6410

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 6411

#Unit 2. Cellular Organization

Attenuator riboswitch (Leader sequence) region 1 is translated atleast till codon 10 and 11 in case of Low trp concentration because ribosomes get stalled due to low availability of charged tRNA-trp

TLS Online TPP Program

#Id: 6412

#Unit 2. Cellular Organization

In case of Low trp concentration, RNA polymerase continues to EDCBA genes where new ribosome get attached to AUG of polycistronic genes