InterPro domain: IPR036346

Obg subfamily proteins (also known as ObgE, YhbZ and CgtA) are conserved P- loop GTPases, that are involved in a wide range of cellular processes, including sporulation, cellular differentiation, ribosome assembly, DNA replication, chromosome segregation, and stringent response in eubacteria and plant chloroplasts. Obg subfamily proteins have three domains: the Obg fold, the G domain, and the Obg C-terminal (OCT) domain. A potential role of the OCT domain in the regulation of the nucleotide-binding state has been suggested [ 1 , 2 , 3 ]. The OCT domain structure contains a four-stranded beta sheet and three alpha helices flanked by an additional beta strand [ 4 ].

This entry represents the OCT domain.

1. Crystal structure of the GTP-binding protein Obg from Thermus thermophilus HB8. J. Mol. Biol. 337, 761-70
2. Functional characterization of ObgC in ribosome biogenesis during chloroplast development. Plant J. 71, 122-34
3. AtObgC, a plant ortholog of bacterial Obg, is a chloroplast-targeting GTPase essential for early embryogenesis. Plant Mol. Biol. 71, 379-90