Structural insights into a new homodimeric self-activated GTPase family

Type Article
Date 2007-06
Language English
Author(s) Gras S1, Chaumont V2, Fernandez B2, Carpentier P1, Charrier Savournin F2, Schmitt Sophie3, Pineau C4, Flament DidierORCID3, Hecker A5, Forterre P5, 6, Armengaud J2, Housset D1
Affiliation(s) 1 : Laboratoire de Cristallographie et Cristallogénèse des Protéines, Institut de Biologie Structurale J.-P. Ebel, CEA-CNRS-UJF, UMR 5075, 41, Rue Jules Horowitz, F-38027 Grenoble, France
2 : Inst Biol Environm & Biotechnol, Serv Biochim & Toxicol Nucl, Lab Biochim Syst Perturbes, Marcoule, Bagnols Ceze, France
3 : IFREMER, Lab Microbiol Environm Extremes, UMR6197, Ctr Brest, Plouzane, France.
4 : INSERM, U625, UPRES, JE 2459, Rennes, France.
5 : Univ Paris 11, CNRS, Inst Genet & Microbiol, UMR 8621, Orsay, France.
6 : Inst Pasteur, Dept Microbiol Fondamentale & Med, Lab Microbiol & Biotechnol Extremophiles, Paris, France.
Source Embo reports (1469-221X) (Nature), 2007-06 , Vol. 8 , N. 6 , P. 569-575
DOI 10.1038/sj.embor.7400958
WOS© Times Cited 40
Keyword(s) Structure, SIMIBI, Replication, GTPase, Crystal
Abstract 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.
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Gras S, Chaumont V, Fernandez B, Carpentier P, Charrier Savournin F, Schmitt Sophie, Pineau C, Flament Didier, Hecker A, Forterre P, Armengaud J, Housset D (2007). Structural insights into a new homodimeric self-activated GTPase family. Embo reports, 8(6), 569-575. Publisher's official version : , Open Access version :