1KQ2

Crystal Structure of an Hfq-RNA Complex

Summary for 1KQ2

• Entry DOI: 10.2210/pdb1kq2/pdb
• Related: 1KQ1
• Descriptor: 5'-R(*AP*UP*UP*UP*UP*UP*G)-3', Host factor for Q beta (3 entities in total)
• Functional Keywords: hfq-rna complex, single-stranded rna, translational regulator, translation-rna complex, translation/rna
• Biological source: Staphylococcus aureus
• Total number of polymer chains: 7
• Total formula weight: 54880.38

Authors

Schumacher, M.A.,Pearson, R.F.,Moller, T.,Valentin-Hansen, P.,Brennan, R.G. (deposition date: 2002-01-03, release date: 2002-07-05, Last modification date: 2023-08-16)

Primary citation

Schumacher, M.A.,Pearson, R.F.,Moller, T.,Valentin-Hansen, P.,Brennan, R.G.
Structures of the pleiotropic translational regulator Hfq and an Hfq-RNA complex: a bacterial Sm-like protein.
EMBO J., 21:3546-3556, 2002

PubMed Abstract: In prokaryotes, Hfq regulates translation by modulating the structure of numerous RNA molecules by binding preferentially to A/U-rich sequences. To elucidate the mechanisms of target recognition and translation regulation by Hfq, we determined the crystal structures of the Staphylococcus aureus Hfq and an Hfq-RNA complex to 1.55 and 2.71 A resolution, respectively. The structures reveal that Hfq possesses the Sm-fold previously observed only in eukaryotes and archaea. However, unlike these heptameric Sm proteins, Hfq forms a homo-hexameric ring. The Hfq-RNA structure reveals that the single-stranded hepta-oligoribonucleotide binds in a circular conformation around a central basic cleft, whereby Tyr42 residues from adjacent subunits stack with six of the bases, and Gln8, outside the Sm motif, provides key protein-base contacts. Such binding suggests a mechanism for Hfq function.

PubMed: 12093755
DOI: 10.1093/emboj/cdf322

Experimental method

X-RAY DIFFRACTION (2.71 Å)