3SB2

Crystal Structure of the RNA chaperone Hfq from Herbaspirillum seropedicae SMR1

Summary for 3SB2

• Entry DOI: 10.2210/pdb3sb2/pdb
• Descriptor: Protein hfq, GLYCEROL (3 entities in total)
• Functional Keywords: sm-like, rna chaperone, chaperone
• Biological source: Herbaspirillum seropedicae
• Total number of polymer chains: 6
• Total formula weight: 53180.86

Authors

Kadowaki, M.A.S.,Iulek, J.,Barbosa, J.A.R.G.,Pedrosa, F.O.,Souza, E.M.,Chubatsu, L.S.,Monteiro, R.A.,Steffens, M.B.R. (deposition date: 2011-06-03, release date: 2012-01-04, Last modification date: 2024-02-28)

Primary citation

Kadowaki, M.A.,Iulek, J.,Barbosa, J.A.R.G.,Pedrosa, F.D.,de Souza, E.M.,Chubatsu, L.S.,Monteiro, R.A.,de Oliveira, M.A.,Steffens, M.B.
Structural characterization of the RNA chaperone Hfq from the nitrogen-fixing bacterium Herbaspirillum seropedicae SmR1.
Biochim.Biophys.Acta, 1824:359-365, 2011

PubMed Abstract: The RNA chaperone Hfq is a homohexamer protein identified as an E. coli host factor involved in phage Qβ replication and it is an important posttranscriptional regulator of several types of RNA, affecting a plethora of bacterial functions. Although twenty Hfq crystal structures have already been reported in the Protein Data Bank (PDB), new insights into these protein structures can still be discussed. In this work, the structure of Hfq from the β-proteobacterium Herbaspirillum seropedicae, a diazotroph associated with economically important agricultural crops, was determined by X-ray crystallography and small-angle X-ray scattering (SAXS). Biochemical assays such as exclusion chromatography and RNA-binding by the electrophoretic shift assay (EMSA) confirmed that the purified protein is homogeneous and active. The crystal structure revealed a conserved Sm topology, composed of one N-terminal α-helix followed by five twisted β-strands, and a novel π-π stacking intra-subunit interaction of two histidine residues, absent in other Hfq proteins. Moreover, the calculated ab initio envelope based on small-angle X-ray scattering (SAXS) data agreed with the Hfq crystal structure, suggesting that the protein has the same folding structure in solution.

PubMed: 22154803
DOI: 10.1016/j.bbapap.2011.11.002

Experimental method

X-RAY DIFFRACTION (2.6301 Å)