2m1c

Publication Abstract from PubMed

The Bacillus subtilis protein YybT (or GdpP) and its homologs were recently established as stress signaling proteins that exert their biological effect by degrading the bacterial messenger c-di-AMP. YybT homologs contain a small Per-ARNT-Sim (PAS) domain (ca. 80 amino acids) that can bind b-type heme with 1:1 stoichiometry despite the small size of the domain and the lack of a conserved heme iron-coordinating residue. We determined the solution structure of the PAS domain of GtYybT from Geobacillus thermodenitrificans by NMR spectroscopy to further probe its function. The solution structure confirms that PASGtYybT adopts the characteristic PAS fold composed of a five-stranded antiparallel beta sheet and a few short alpha-helices. One alpha-helix and three central beta-strands of PASGtYybT are noticeably shorter than those of the typical PAS domains. Despite the small size of the protein domain, a hydrophobic pocket is formed by the side chains of non-polar residues stemming from the beta-strands and alpha-helices. A set of residues in the vicinity of the pocket and in the C-terminal region at the dimeric interface exhibit perturbed NMR parameters in the presence of heme or zinc protoporphyrin. Together, the results unveil a compact PAS domain with a potential ligand-binding pocket and reinforce the view that the PASYybT domains function as regulatory domains in the modulation of cellular c-di-AMP concentration.

Solution Structure of the PAS Domain of a Thermophilic YybT Homolog Reveals a Potential Ligand-Binding Site.,Tan E, Rao F, Pasunooti S, Pham TH, Soehano I, Turner MS, Liew CW, Lescar J, Pervushin K, Liang ZX J Biol Chem. 2013 Mar 15. PMID:23504327^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.