A new MgGDP complex of the Ffh NG domainA new MgGDP complex of the Ffh NG domain

Structural highlights

1o87 is a 2 chain structure with sequence from Thermus aquaticus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.1Å
Ligands:, , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

SRP54_THEAQ Involved in targeting and insertion of nascent membrane proteins into the cytoplasmic membrane. Binds to the hydrophobic signal sequence of the ribosome-nascent chain (RNC) as it emerges from the ribosomes. The SRP-RNC complex is then targeted to the cytoplasmic membrane where it interacts with the SRP receptor FtsY (By similarity).[HAMAP-Rule:MF_00306]

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Ffh is the signal sequence recognition and targeting subunit of the prokaryotic signal recognition particle (SRP). Previous structural studies of the NG GTPase domain of Ffh demonstrated magnesium-dependent and magnesium-independent binding conformations for GDP and GMPPNP that are believed to reflect novel mechanisms for exchange and activation in this member of the GTPase superfamily. The current study of the NG GTPase bound to Mg(2+)GDP reveals two new binding conformations-in the first the magnesium interactions are similar to those seen previously, however, the protein undergoes a conformational change that brings a conserved aspartate into its second coordination sphere. In the second, the protein conformation is similar to that seen previously, but the magnesium coordination sphere is disrupted so that only five oxygen ligands are present. The loss of the coordinating water molecule, at the position that would be occupied by the oxygen of the gamma-phosphate of GTP, is consistent with that position being privileged for exchange during phosphate release. The available structures of the GDP-bound protein provide a series of structural snapshots that illuminate steps along the pathway of GDP release following GTP hydrolysis.

Novel protein and Mg2+ configurations in the Mg2+GDP complex of the SRP GTPase ffh.,Focia PJ, Alam H, Lu T, Ramirez UD, Freymann DM Proteins. 2004 Feb 1;54(2):222-30. PMID:14696184[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Focia PJ, Alam H, Lu T, Ramirez UD, Freymann DM. Novel protein and Mg2+ configurations in the Mg2+GDP complex of the SRP GTPase ffh. Proteins. 2004 Feb 1;54(2):222-30. PMID:14696184 doi:10.1002/prot.10598

1o87, resolution 2.10Å

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