pfam04012: PspA_IM30 (this model, PSSM-Id:112811 is obsolete and has been replaced by 281941)
This family includes PspA a protein that suppresses sigma54-dependent transcription. The PspA protein, a negative regulator of the Escherichia coli phage shock psp operon, is produced when virulence factors are exported through secretins in many Gram-negative pathogenic bacteria and its homologue in plants, VIPP1, plays a critical role in thylakoid biogenesis, essential for photosynthesis. Activation of transcription by the enhancer-dependent bacterial sigma(54) containing RNA polymerase occurs through ATP hydrolysis-driven protein conformational changes enabled by activator proteins that belong to the large AAA(+) mechanochemical protein family. It has been shown that PspA directly and specifically acts upon and binds to the AAA(+) domain of the PspF transcription activator.