A Region in Bacillus subtilis ς ^H Required for Spo0A-Dependent Promoter Activity

Abstract

Spo0A activates transcription in Bacillus subtilis from promoters that are used by two types of RNA polymerase, RNA polymerase containing the primary sigma factor, ςA, and RNA polymerase containing a secondary sigma factor, known as ςH. The region of ςA near positions 356 to 359 is required for Spo0A-dependent promoter activation, possibly because Spo0A interacts with this region of ςA at these promoters. To determine if the amino acids in the corresponding region of ςH are also important in Spo0A-dependent promoter activation, we examined the effects of single alanine substitutions at 10 positions in ςH (201 to 210). Two alanine substitutions in ςH, at glutamine 201 (Q201A) and at arginine 205 (R205A), significantly decreased activity from the Spo0A-dependent, ςH-dependent promoterspoIIA but did not affect expression from the ςH-dependent, Spo0A-independent promoterscitGp2 and spoVG. Therefore, promoter activation by Spo0A requires homologous regions in ςA and ςH. A mutant form of Spo0A, S231F, that suppresses the sporulation defect caused by several amino acid substitutions in ςA did not suppress the sporulation defects caused by the Q201A and R205A substitutions in ςH. This result and others indicate that different surfaces of Spo0A probably interact with ςA and ςH RNA polymerases.

Phosphorylation and functional analysis of the sporulation initiation factor Spo0A from Clostridium botulinum

“…The most probable reason for this conservation is that Spo0A must interact with other proteins whose amino acid sequences are conserved. It is known to interact with RNA polymerases containing either Sigma A or Sigma H (Buckner and Moran, 1998). The αE region of Spo0A in which mutations affect Sigma A‐dependent transcription (Buckner and Moran, 1998; Hatt and Youngman, 1998) shows significant amino acid variability in the two species (Fig.…”

The trans‐activation domain of the sporulation response regulator Spo0A revealed by X‐ray crystallography

“…As for σ A , mutations in region 4.2 of σ H specifically decrease Spo0A∼P‐dependent stimulation of transcription directed by E‐σ H . Thus, the Q201A and R205A substitutions in σ H reduce Spo0A‐dependent transcription by E‐σ H from the spoIIA promoter without affecting transcription by E‐σ H from the spoVG promoter, which is Spo0A‐independent (Buckner and Moran, 1998). It seems therefore that Spo0A‐dependent transcription requires homologous regions of σ A and σ H .…”

Interactions between activating region 3 of the Escherichia coli cyclic AMP receptor protein and region 4 of the RNA polymerase σ 70 subunit: application of suppression genetics 1 1Edited by R. Ebright

“…In contrast, His, Cys and Ser substitutions at position 596 of s 70 reduce MalT-dependent activation of PmalK-lamB (Hu & Gross, 1985), and Lonetto et al (1998) demonstrated that FNR requires R596 for activation of PdmsA, and also PnarG in the absence of the co-regulator, NarL. In addition, at the Bacillus subtilis s H -dependent promoter, spoIIA, the Spo0A transcription factor requires the equivalent residue of s H , R205, to activate transcription (Buckner & Moran, 1998). Thus R596 in s 70 plays an important role in transcription activation at a variety of activator-dependent promoters.…”