X-ray structure of the T. aquaticus Ftsy:GDP complex suggests functional roles for the C-terminal helix of the SRP GTPases

Joseph Gawronski-Salerno, John S. Coon V, Pamela J. Focia, Douglas M. Freymann*

*Corresponding author for this work

Research output: Contribution to journalArticle

21 Scopus citations

Abstract

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 Å 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.

Original languageEnglish (US)
Pages (from-to)984-995
Number of pages12
JournalProteins: Structure, Function and Genetics
Volume66
Issue number4
DOIs
StatePublished - Mar 2007

Keywords

  • Ffh
  • FtsY
  • GDP
  • GTPase
  • SR
  • SRP
  • X-ray crystallography

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • Molecular Biology

Fingerprint Dive into the research topics of 'X-ray structure of the T. aquaticus Ftsy:GDP complex suggests functional roles for the C-terminal helix of the SRP GTPases'. Together they form a unique fingerprint.

Cite this