1YR9: Pab0955 Crystal Structure : A Gtpase In Gdp And Po4 Bound Form From Pyrococcus Abyssi

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.
PDB ID: 1YR9Download
MMDB ID: 37454
PDB Deposition Date: 2005/2/3
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2.8  Å
Source Organism:
Similar Structures:
Biological Unit for 1YR9: dimeric; determined by author and by software (PISA,PQS)
Molecular Components in 1YR9
Label Count Molecule
Proteins (2 molecules)
Atp(gtp)binding Protein(Gene symbol: PAB_RS07735)
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

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