6QW1

The Transcriptional Regulator PrfA-L140F mutant from Listeria Monocytogenes

Summary for 6QW1

• Entry DOI: 10.2210/pdb6qw1/pdb
• Descriptor: Listeriolysin positive regulatory factor A, ISOPROPYL ALCOHOL, SODIUM ION, ... (4 entities in total)
• Functional Keywords: transcription regulator, activation, listeria monocytogenes, transcription, virulence factor, dna binding protein
• Biological source: Listeria monocytogenes
• Total number of polymer chains: 2
• Total formula weight: 55472.71

Authors

Hall, M.,Grundstrom, C.,Hansen, S.,Brannstrom, K.,Johansson, J.,Sauer-Eriksson, A.E. (deposition date: 2019-03-05, release date: 2020-04-01, Last modification date: 2024-01-24)

Primary citation

Hansen, S.,Hall, M.,Grundstrom, C.,Brannstrom, K.,Sauer-Eriksson, A.E.,Johansson, J.
A Novel Growth-Based Selection Strategy Identifies New Constitutively Active Variants of the Major Virulence Regulator PrfA in Listeria monocytogenes.
J.Bacteriol., 202:-, 2020

PubMed Abstract: is a Gram-positive pathogen able to cause severe human infections. Its major virulence regulator is the transcriptional activator PrfA, a member of the Crp/Fnr family of transcriptional regulators. To establish a successful infection, the PrfA protein needs to be in an active conformation, either by binding the cognate inducer glutathione (GSH) or by possessing amino acid substitutions rendering the protein constitutively active (PrfA*). By a yet unknown mechanism, phosphotransferase system (PTS) sugars repress the activity of PrfA. We therefore took a transposon-based approach to identify the mechanism by which PTS sugars repress PrfA activity. For this, we screened a transposon mutant bank to identify clones able to grow in the presence of glucose-6-phosphate as the sole carbon source. Surprisingly, most of the isolated transposon mutants also carried amino acid substitutions in PrfA. In transposon-free strains, the PrfA amino acid substitution mutants displayed growth, virulence factor expression, infectivity, and DNA binding, agreeing with previously identified PrfA* mutants. Hence, the initial growth phenotype observed in the isolated clone was due to the amino acid substitution in PrfA and unrelated to the loci inactivated by the transposon mutant. Finally, we provide structural evidence for the existence of an intermediately activated PrfA state, which gives new insights into PrfA protein activation. The Gram-positive bacterium is a human pathogen affecting mainly the elderly, immunocompromised people, and pregnant women. It can lead to meningoencephalitis, septicemia, and abortion. The major virulence regulator in is the PrfA protein, a transcriptional activator. Using a growth-based selection strategy, we identified mutations in the PrfA protein leading to constitutively active virulence factor expression. We provide structural evidence for the existence of an intermediately activated PrfA state, which gives new insights into PrfA protein activation.

PubMed: 32179627
DOI: 10.1128/JB.00115-20

Experimental method

X-RAY DIFFRACTION (1.844 Å)