2hf9
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Crystal structure of HypB from Methanocaldococcus jannaschii in the triphosphate form
OverviewOverview
HypB is a prokaryotic metal-binding guanine nucleotide-binding protein, that is essential for nickel incorporation into hydrogenases. Here we, solved the x-ray structure of HypB from Methanocaldococcus jannaschii. It, shows that the G-domain has a different topology than the Ras-like, proteins and belongs to the SIMIBI (after Signal Recognition Particle, MinD and BioD) class of NTP-binding proteins. We show that HypB undergoes, nucleotide-dependent dimerization, which is apparently a common feature of, SIMIBI class G-proteins. The nucleotides are located in the dimer, interface and are contacted by both subunits. The active site features, residues from both subunits arguing that hydrolysis also requires, dimerization. Two metal-binding sites are found, one of which is dependent, on the state of bound nucleotide. A totally conserved ENV/IGNLV/ICP motif, in switch II relays the nucleotide binding with the metal ionbinding site., The homology with NifH, the Fe protein subunit of nitrogenase, suggests a, mechanistic model for the switch-dependent incorporation of a metal ion, into hydrogenases.
About this StructureAbout this Structure
2HF9 is a Single protein structure of sequence from Methanocaldococcus jannaschii with MG, ZN and GSP as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Structural insights into HypB, a GTP-binding protein that regulates metal binding., Gasper R, Scrima A, Wittinghofer A, J Biol Chem. 2006 Sep 15;281(37):27492-502. Epub 2006 Jun 28. PMID:16807243
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