3lx5 | pdb_00003lx5

Crystal structure of mGMPPNP-bound NFeoB from S. thermophilus

spinqualitylabelsall models 3lx5, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3lx5 is a 1 chain structure with sequence from Streptococcus thermophilus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: AGO, GOL, MG Related: 3lx8 Gene: feoB, stu0608 (Streptococcus thermophilus) Resources: FirstGlance, OCA, RCSB, PDBsum 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 FeoB is a prokaryotic membrane protein responsible for the import of ferrous iron (Fe(2+)). A defining feature of FeoB is that it includes an N-terminal 30-kDa soluble domain with GTPase activity, which is required for iron transport. However, the low intrinsic GTP hydrolysis rate of this domain appears to be too slow for FeoB either to function as a channel or to possess an active Fe(2+) membrane transport mechanism. Here, we present crystal structures of the soluble domain of FeoB from Streptococcus thermophilus in complex with GDP and with the GTP analogue derivative 2'-(or -3')-O-(N-methylanthraniloyl)-beta,gamma-imidoguanosine 5'-triphosphate (mant-GMPPNP). Unlike recent structures of the G protein domain, the mant-GMPPNP-bound structure shows clearly resolved, active conformations of the critical Switch motifs. Importantly, biochemical analyses demonstrate that the GTPase activity of FeoB is activated by K(+), which leads to a 20-fold acceleration in its hydrolysis rate. Analysis of the structure identified a conserved asparagine residue likely to be involved in K(+) coordination, and mutation of this residue abolished K(+)-dependent activation. We suggest that this, together with a second asparagine residue that we show is critical for the structure of the Switch I loop, allows the prediction of K(+)-dependent activation in G proteins. In addition, the accelerated hydrolysis rate opens up the possibility that FeoB might indeed function as an active transporter. Potassium-activated GTPase reaction in the G Protein-coupled ferrous iron transporter B.,Ash MR, Guilfoyle A, Clarke RJ, Guss JM, Maher MJ, Jormakka M J Biol Chem. 2010 May 7;285(19):14594-602. Epub 2010 Mar 10. PMID:20220129 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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