2Q9B: Structure Of Ftsy:gmppnp Complex

Citation:
Abstract
The signal recognition particle (SRP) and its conjugate receptor (SR) mediate cotranslational targeting of a subclass of proteins destined for secretion to the endoplasmic reticulum membrane in eukaryotes or to the plasma membrane in prokaryotes. Conserved active site residues in the GTPase domains of both SRP and SR mediate discrete conformational changes during formation and dissociation of the SRP.SR complex. Here, we describe structures of the prokaryotic SR, FtsY, as an apo protein and in two different complexes with a non-hydrolysable GTP analog (GMPPNP). These structures reveal intermediate conformations of FtsY containing GMPPNP and explain how the conserved active site residues position the nucleotide into a non-catalytic conformation. The basis for the lower specificity of binding of nucleotide in FtsY prior to heterodimerization with the SRP conjugate Ffh is also shown. We propose that these structural changes represent discrete conformational states assumed by FtsY during targeting complex formation and dissociation.
PDB ID: 2Q9BDownload
MMDB ID: 47273
PDB Deposition Date: 2007/6/12
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 2.3  Å
Source Organism:
Similar Structures:
Biological Unit for 2Q9B: monomeric; determined by author and by software (PQS)
Molecular Components in 2Q9B
Label Count Molecule
Protein (1 molecule)
1
Cell Division Protein Ftsy
Molecule annotation
Chemicals (12 molecules)
1
7
2
4
3
1
* Click molecule labels to explore molecular sequence information.

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