2hf9
Crystal structure of HypB from Methanocaldococcus jannaschii in the triphosphate formCrystal structure of HypB from Methanocaldococcus jannaschii in the triphosphate form
Structural highlights
FunctionHYPB_METJA Could be involved in nickel binding and accumulation. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedHypB 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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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