Role of the ribosome-associated protein PY in the cold-shock response of Escherichia coli
Article first published online: 19 FEB 2013
© 2013 The Authors. MicrobiologyOpen published by Blackwell Publishing Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Volume 2, Issue 2, pages 293–307, April 2013
How to Cite
Di Pietro, F., Brandi, A., Dzeladini, N., Fabbretti, A., Carzaniga, T., Piersimoni, L., Pon, C. L. and Giuliodori, A. M. (2013), Role of the ribosome-associated protein PY in the cold-shock response of Escherichia coli. MicrobiologyOpen, 2: 293–307. doi: 10.1002/mbo3.68
- Issue published online: 8 APR 2013
- Article first published online: 19 FEB 2013
- Manuscript Accepted: 28 DEC 2012
- Manuscript Revised: 18 DEC 2012
- Manuscript Received: 11 OCT 2012
- MIUR. Grant Number: PRIN 2007
- Cold shock;
- protein PY;
- translation initiation;
- translation regulation
Protein Y (PY) is an Escherichia coli cold-shock protein which has been proposed to be responsible for the repression of bulk protein synthesis during cold adaptation. Here, we present in vivo and in vitro data which clarify the role of PY and its mechanism of action. Deletion of yfiA, the gene encoding protein PY, demonstrates that this protein is dispensable for cold adaptation and is not responsible for the shutdown of bulk protein synthesis at the onset of the stress, although it is able to partially inhibit translation. In vitro assays reveal that the extent of PY inhibition changes with different mRNAs and that this inhibition is related to the capacity of PY of binding 30S subunits with a fairly strong association constant, thus stimulating the formation of 70S monomers. Furthermore, our data provide evidence that PY competes with the other ribosomal ligands for the binding to the 30S subunits. Overall these results suggest an alternative model to explain PY function during cold shock and to reconcile the inhibition caused by PY with the active translation observed for some mRNAs during cold shock.