2oxr
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PAB0955 crystal structure : a GTPase in GDP and Mg bound form from Pyrococcus abyssi (after GTP hydrolysis)
OverviewOverview
The human XAB1/MBDin GTPase and its close homologues form one of the ten phylogenetically distinct families of the SIMIBI (after signal recognition particle, MinD and BioD) class of phosphate-binding loop NTPases. The genomic context and the partners identified for the archaeal and eukaryotic homologues indicate that they are involved in genome maintenance--DNA repair or replication. The crystal structure of PAB0955 from Pyrococcus abyssi shows that, unlike other SIMIBI class G proteins, these highly conserved GTPases are homodimeric, regardless of the presence of nucleotides. The nucleotide-binding site of PAB0955 is rather rigid and its conformation is closest to that of the activated SRP G domain. One insertion to the G domain bears a strictly conserved GPN motif, which is part of the catalytic site of the other monomer and stabilizes the phosphate ion formed. Owing to this unique functional feature, we propose to call this family as GPN-loop GTPase.
About this StructureAbout this Structure
2OXR is a Single protein structure of sequence from Pyrococcus abyssi with and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Structural insights into a new homodimeric self-activated GTPase family., Gras S, Chaumont V, Fernandez B, Carpentier P, Charrier-Savournin F, Schmitt S, Pineau C, Flament D, Hecker A, Forterre P, Armengaud J, Housset D, EMBO Rep. 2007 Jun;8(6):569-75. Epub 2007 Apr 20. PMID:17468740
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