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Structural Insights into HypB, a GTP-binding Protein That Regulates Metal Binding.
- Source :
-
Journal of Biological Chemistry . 9/15/2006, Vol. 281 Issue 37, p27492-27502. 11p. 3 Diagrams, 2 Charts, 3 Graphs. - Publication Year :
- 2006
-
Abstract
- 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 Met hanocaldococcus 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 com- mon 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 ion-binding 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. [ABSTRACT FROM AUTHOR]
- Subjects :
- *G proteins
*MEMBRANE proteins
*IONS
*NUCLEIC acids
*HYDROGENASE
Subjects
Details
- Language :
- English
- ISSN :
- 00219258
- Volume :
- 281
- Issue :
- 37
- Database :
- Academic Search Index
- Journal :
- Journal of Biological Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 22576449
- Full Text :
- https://doi.org/10.1074/jbc.M600809200