Protein Family Models

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 [2]. [1]. 10629175. The PspA protein of Escherichia coli is a negative regulator of sigma(54)-dependent transcription. Dworkin J, Jovanovic G, Model P;. J Bacteriol 2000;182:311-319. [2]. 12079332. Mechanism of Action of the Escherichia coli Phage Shock Protein PspA in Repression of the AAA Family Transcription Factor PspF. Elderkin S, Jones S, Schumacher J, Studholme D, Buck M;. J Mol Biol 2002;320:23-37. (from Pfam)

Date:

2024-10-16

phage shock protein PspA negatively regulates expression of the pspABCDE promoter and of pspG through negative regulation of the psp-specific transcriptional activator PspF; it is also required for membrane integrity, efficient translocation and maintenance of the proton motive force

Date:

2019-06-28

Members of this family are the phage shock protein PspA, from the phage shock operon. This is a narrower family than the set of PspA and its homologs, sometimes several in a genome, as described by PFAM model PF04012. PspA appears to maintain the protonmotive force under stress conditions that include overexpression of certain phage secretins, heat shock, ethanol, and protein export defects.

Gene:

pspA

Date:

2019-09-10

Gene:

pspA

Date:

2020-10-26