2px0: Difference between revisions

Revision as of 19:33, 21 February 2008

Crystal structure of FlhF complexed with GMPPNP/Mg(2+)

OverviewOverview

Flagella are well characterized as the organelles of locomotion and allow bacteria to react to environmental changes. The assembly of flagella is a multistep process and relies on a complex type III export machinery located in the cytoplasmic membrane. The FlhF protein is essential for the placement and assembly of polar flagella and has been classified as a signal-recognition particle (SRP)-type GTPase. SRP GTPases appeared early in evolution and form a unique subfamily within the guanine nucleotide binding proteins with only three members: the signal sequence-binding protein SRP54, the SRP receptor FtsY, and FlhF. We report the crystal structures of FlhF from Bacillus subtilis in complex with GTP and GMPPNP. FlhF shares SRP GTPase-specific features such as the presence of an N-terminal alpha-helical domain and the I-box insertion. It forms a symmetric homodimer sequestering a composite active site that contains two head-to-tail arranged nucleotides similar to the heterodimeric SRP-targeting complex. However, significant differences to the GTPases of SRP and the SRP receptor include the formation of a stable homodimer with GTP as well as severe modifications and even the absence of motifs involved in regulation of the other two SRP GTPases. Our results provide insights into SRP GTPases and their roles in two fundamentally different protein-targeting routes that both rely on efficient protein delivery to a secretion channel.

About this StructureAbout this Structure

2PX0 is a Single protein structure of sequence from Bacillus subtilis with and as ligands. Full crystallographic information is available from OCA.

ReferenceReference

The crystal structure of the third signal-recognition particle GTPase FlhF reveals a homodimer with bound GTP., Bange G, Petzold G, Wild K, Parlitz RO, Sinning I, Proc Natl Acad Sci U S A. 2007 Aug 21;104(34):13621-5. Epub 2007 Aug 15. PMID:17699634

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 ==Overview==
-Flagella are well characterized as the organelles of locomotion and allow, bacteria to react to environmental changes. The assembly of flagella is a, multistep process and relies on a complex type III export machinery, located in the cytoplasmic membrane. The FlhF protein is essential for the, placement and assembly of polar flagella and has been classified as a, signal-recognition particle (SRP)-type GTPase. SRP GTPases appeared early, in evolution and form a unique subfamily within the guanine nucleotide, binding proteins with only three members: the signal sequence-binding, protein SRP54, the SRP receptor FtsY, and FlhF. We report the crystal, structures of FlhF from Bacillus subtilis in complex with GTP and GMPPNP., FlhF shares SRP GTPase-specific features such as the presence of an, N-terminal alpha-helical domain and the I-box insertion. It forms a, symmetric homodimer sequestering a composite active site that contains two, head-to-tail arranged nucleotides similar to the heterodimeric, SRP-targeting complex. However, significant differences to the GTPases of, SRP and the SRP receptor include the formation of a stable homodimer with, GTP as well as severe modifications and even the absence of motifs, involved in regulation of the other two SRP GTPases. Our results provide, insights into SRP GTPases and their roles in two fundamentally different, protein-targeting routes that both rely on efficient protein delivery to a, secretion channel.
+Flagella are well characterized as the organelles of locomotion and allow bacteria to react to environmental changes. The assembly of flagella is a multistep process and relies on a complex type III export machinery located in the cytoplasmic membrane. The FlhF protein is essential for the placement and assembly of polar flagella and has been classified as a signal-recognition particle (SRP)-type GTPase. SRP GTPases appeared early in evolution and form a unique subfamily within the guanine nucleotide binding proteins with only three members: the signal sequence-binding protein SRP54, the SRP receptor FtsY, and FlhF. We report the crystal structures of FlhF from Bacillus subtilis in complex with GTP and GMPPNP. FlhF shares SRP GTPase-specific features such as the presence of an N-terminal alpha-helical domain and the I-box insertion. It forms a symmetric homodimer sequestering a composite active site that contains two head-to-tail arranged nucleotides similar to the heterodimeric SRP-targeting complex. However, significant differences to the GTPases of SRP and the SRP receptor include the formation of a stable homodimer with GTP as well as severe modifications and even the absence of motifs involved in regulation of the other two SRP GTPases. Our results provide insights into SRP GTPases and their roles in two fundamentally different protein-targeting routes that both rely on efficient protein delivery to a secretion channel.
 ==About this Structure==
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 [[Category: srp gtpase]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 13:28:21 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:33:50 2008''