3m4g

Publication Abstract from PubMed

The bacterial Sm-like protein Hfq forms homohexamers both in solution and in crystals. The monomers are organized as a continuous beta-sheet passing through the whole hexamer ring with a common hydrophobic core. Analysis of the Pseudomonas aeruginosa Hfq (PaeHfq) hexamer structure suggested that solvent-inaccessible intermonomer hydrogen bonds created by conserved amino-acid residues should also stabilize the quaternary structure of the protein. In this work, one such conserved residue, His57, in PaeHfq was replaced by alanine, threonine or asparagine. The crystal structures of His57Thr and His57Ala Hfq were determined and the stabilities of all of the mutant forms and of the wild-type protein were measured. The results obtained demonstrate the great importance of solvent-inaccessible conserved hydrogen bonds between the Hfq monomers in stabilization of the hexamer structure.

The structures of mutant forms of Hfq from Pseudomonas aeruginosa reveal the importance of the conserved His57 for the protein hexamer organization.,Moskaleva O, Melnik B, Gabdulkhakov A, Garber M, Nikonov S, Stolboushkina E, Nikulin A Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010 Jul 1;66(Pt, 7):760-4. Epub 2010 Jun 23. PMID:20606268^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.