1hk9: Difference between revisions

[[Image:1hk9.jpg|left|200px]]<br /><applet load="1hk9" size="350" color="white" frame="true" align="right" spinBox="true"  

The Hfq protein was discovered in Escherichia coli in the early seventies as a host factor for the Qbeta phage RNA replication. During the last decade, it was shown to be involved in many RNA processing events and remote sequence homology indicated a link to spliceosomal Sm proteins. We report the crystal structure of the E.coli Hfq protein showing that its monomer displays a characteristic Sm-fold and forms a homo-hexamer, in agreement with former biochemical data. Overall, the structure of the E.coli Hfq ring is similar to the one recently described for Staphylococcus aureus. This confirms that bacteria contain a hexameric Sm-like protein which is likely to be an ancient and less specialized form characterized by a relaxed RNA binding specificity. In addition, we identified an Hfq ortholog in the archaeon Methanococcus jannaschii which lacks a classical Sm/Lsm gene. Finally, a detailed structural comparison shows that the Sm-fold is remarkably well conserved in bacteria, Archaea and Eukarya, and represents a universal and modular building unit for oligomeric RNA binding proteins.

1HK9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HK9 OCA].  

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:02:14 2008''