The lacUV5 promoter is insensitive to catabolite repression, the level of expression from this promoter is unaffected by cAMP and is virtually constant at different growth rates. LacUV5 is a mutated variant from of the lac promoter found in Escherichia coli. The lacUV5 mutated promoter varies from the lac promoter sequence by 2 bases within the -10 consensus (TATGTT in lac promter; TATAAT in lacUV5) and lacUV5 is lacking the CAP binding site for cAMP regulation. The lacUV5 promoter is much stronger than the lac promoter. Even though lacUV5 is considered strong relative to other E. coli promoters, it is still weak when compared to T7 promoters. This part includes the lacUV5 promoter and lac operator sequence.