. 2010 Apr 9;192(12):3103–3113. doi: 10.1128/JB.00089-10

TABLE 1.

Characteristics of each promoter identified within the phoPR operon promoter region

phoPR promoter	Position^a	σ Factor^b	Activator	Repressor
P_A6	−175	σ^A		CcpA
P₅	−93	Unknown^c	Unknown^d	Unknown
P_A4	−69	σ^A	PhoP∼P
P_A3	−48 to −49	σ^A	Unknown^e
P_E2	−36 to −38	σ^E	PhoP∼P
P_B1	−23	σ^B

Relative to the A, position +1, of the translation start site, ATG.

Identified by in vitro transcription using core RNAP with purified sigma factor (27, 32).

Not Eσ^A, Eσ^B, Eσ^E, or Eσ^H responsive (Paul and Hulett, unpublished data).

Transcript observed in only a σ^B mutant (27, 32).

Missing or poor −35 element; very weak promoter in vitro compared to in vivo; probably missing activator(s) in vitro (27, 32).