Structural highlights
Function
[OBG_THET8] An essential GTPase which binds GTP, GDP and possibly (p)ppGpp with moderate affinity, with high nucleotide exchange rates and a fairly low GTP hydrolysis rate (By similarity). It may play a role in control of the cell cycle, stress response, ribosome biogenesis and in those bacteria that undergo differentiation, in morphogenesis control (Potential).[HAMAP-Rule:MF_01454]
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 PubMed
Obg comprises a unique family of high-molecular mass GTPases conserved from bacteria to eukaryotes. Bacterial Obg is essential for cellular growth, sporulation, and differentiation. Here, we report the crystal structure of the full-length form of Obg from Thermus thermophilus HB8 at 2.07 A resolution, in the nucleotide-free state. It reveals a three-domain arrangement, composed of the N-terminal domain, the guanine nucleotide-binding domain (G domain), and the C-terminal domain. The N-terminal and G domains have the Obg fold and the Ras-like fold, respectively. These global folds are similar to those of the recently published structure of the C-terminal domain-truncated form of Obg from Bacillus subtilis. On the other hand, the C-terminal domain of Obg was found to have a novel fold (the OCT fold). A comparison of the T.thermophilus and B.subtilis nucleotide-free Obg structures revealed significant conformational changes in the switch-I and switch-II regions of the G domain. Notably, the N-terminal domain is rotated drastically, by almost 180 degrees, around the G domain axis. In the T.thermophilus Obg crystal, the nucleotide-binding site of the G domain interacts with the C-terminal domain of the adjacent molecule. These data suggest a possible domain rearrangement of Obg, and a potential role of the C-terminal domain in the regulation of the nucleotide-binding state.
Crystal structure of the GTP-binding protein Obg from Thermus thermophilus HB8.,Kukimoto-Niino M, Murayama K, Inoue M, Terada T, Tame JR, Kuramitsu S, Shirouzu M, Yokoyama S J Mol Biol. 2004 Mar 26;337(3):761-70. PMID:15019792[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Kukimoto-Niino M, Murayama K, Inoue M, Terada T, Tame JR, Kuramitsu S, Shirouzu M, Yokoyama S. Crystal structure of the GTP-binding protein Obg from Thermus thermophilus HB8. J Mol Biol. 2004 Mar 26;337(3):761-70. PMID:15019792 doi:10.1016/j.jmb.2004.01.047
