2IYL : Structure of an FtsY:GDP complex

  • Pamela J Focia (Contributor)
  • Douglas M. Freymann (Northwestern University) (Contributor)



Experimental Technique/Method:X-RAY DIFFRACTION
Classification:CELL CYCLE
Release Date:2007-01-02
Deposition Date:2006-07-18
Revision Date:2011-05-08#2011-07-13
Molecular Weight:31399.91
Macromolecule Type:Protein
Residue Count:284
Atom Site Count:2112

FtsY and Ffh are structurally similar prokaryotic Signal Recognition Particle GTPases that play an essential role in the Signal Recognition Particle (SRP)-mediated cotranslational targeting of proteins to the membrane. The two GTPases assemble in a GTP-dependent manner to form a heterodimeric SRP targeting complex. We report here the 2.1 A X-ray structure of FtsY from T. aquaticus bound to GDP. The structure of the monomeric protein reveals, unexpectedly, canonical binding interactions for GDP. A comparison of the structures of the monomeric and complexed FtsY NG GTPase domain suggests that it undergoes a conformational change similar to that of Ffh NG during the assembly of the symmetric heterodimeric complex. However, in contrast to Ffh, in which the C-terminal helix shifts independently of the other subdomains, the C-terminal helix and N domain of T. aquaticus FtsY together behave as a rigid body during assembly, suggesting distinct mechanisms by which the interactions of the NG domain "module" are regulated in the context of the two SRP GTPases.
Date made available2007

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