The hisLGDCBHAFI operon codes for the enzymes of the histidine biosynthesis pathway. It is controlled by attenuation in response to histidine availability. When histidine is abundant, the ribosome quickly translates through a stretch of seven histidine codons in the hisL leader region, allowing formation of the transcriptional terminator between hisL and hisG. In contrast, when histidine is not available, the ribosome stalls within the leader region and the terminator will not form, allowing transcription to continue [Di78, Verde81, Frunzio81].
Guanosine tetraphosphate (ppGpp) increases the transcription of the hisLp promoter. In contrast, ppGpp reduces the transcription of other promoters, such as argTp and rrnBp1.
Absolute Position of Transcription Start Site: 2087989 base pairs
Position relative to start of first gene (hisL): -31
|DksA-ppGpp activates transcription [Lee12]||
Di78: Di Nocera PP, Blasi F, Di Lauro R, Frunzio R, Bruni CB (1978). "Nucleotide sequence of the attenuator region of the histidine operon of Escherichia coli K-12." Proc Natl Acad Sci U S A 75(9);4276-80. PMID: 360215
Frunzio81: Frunzio R, Bruni CB, Blasi F (1981). "In vivo and in vitro detection of the leader RNA of the histidine operon of Escherichia coli K-12." Proc Natl Acad Sci U S A 78(5);2767-71. PMID: 6166940
Verde81: Verde P, Frunzio R, di Nocera PP, Blasi F, Bruni CB (1981). "Identification, nucleotide sequence and expression of the regulatory region of the histidine operon of Escherichia coli K-12." Nucleic Acids Res 9(9);2075-86. PMID: 6170941
©2016 SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025-3493