9GU5

Crystal Structure of Hfq V22A

Summary for 9GU5

• Entry DOI: 10.2210/pdb9gu5/pdb
• Descriptor: RNA-binding protein Hfq, RNA (5'-R(P*AP*AP*AP*A)-3'), MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: rna-chaperone, hydrolase
• Biological source: Escherichia coli (strain K12); More
• Total number of polymer chains: 13
• Total formula weight: 135111.78

Authors

McQuail, J.,Krepl, M.,Katsuya-Gaviria, K.,Tabib-Salazar, A.,Burchell, L.,Bischler, T.,Grafenhan, T.,Brear, P.,Luisi, B. (deposition date: 2024-09-18, release date: 2025-02-05)

Primary citation

McQuail, J.,Krepl, M.,Katsuya-Gaviria, K.,Tabib-Salazar, A.,Burchell, L.,Bischler, T.,Grafenhan, T.,Brear, P.,Sponer, J.,Luisi, B.F.,Wigneshweraraj, S.
Transcriptome-scale analysis uncovers conserved residues in the hydrophobic core of the bacterial RNA chaperone Hfq required for small regulatory RNA stability.
Nucleic Acids Res., 53:-, 2025

PubMed Abstract: The RNA chaperone Hfq plays crucial roles in bacterial gene expression and is a major facilitator of small regulatory RNA (sRNA) action. The toroidal architecture of the Hfq hexamer presents three well-characterized surfaces that allow it to bind sRNAs to stabilize them and engage target transcripts. Hfq-interacting sRNAs are categorized into two classes based on the surfaces they use to bind Hfq. By characterizing a systematic alanine mutant library of Hfq to identify amino acid residues that impact survival of Escherichia coli experiencing nitrogen (N) starvation, we corroborated the important role of the three RNA-binding surfaces for Hfq function. We uncovered two, previously uncharacterized, conserved residues, V22 and G34, in the hydrophobic core of Hfq, to have a profound impact on Hfq's RNA-binding activity in vivo. Transcriptome-scale analysis revealed that V22A and G34A Hfq mutants cause widespread destabilization of both sRNA classes, to the same extent as seen in bacteria devoid of Hfq. However, the alanine substitutions at these residues resulted in only modest alteration in stability and structure of Hfq. We propose that V22 and G34 have impact on Hfq function, especially critical under cellular conditions when there is an increased demand for Hfq, such as N starvation.

PubMed: 39868539
DOI: 10.1093/nar/gkaf019

Experimental method

X-RAY DIFFRACTION (2.9 Å)