title: Structure based energy calculation to determine the regulation of G protein signalling by RGS and RGS-G protein interaction specificity.
abstract: The RGS proteins act as GTPase activating proteins and therefore regulate the lifespan of the active G alpha-GTP by accelerating the GTP hydrolysis. Modulatory residues in the RGS protein are present at the periphery of the RGS domain-G protein interface which is essential to fine-tune the G protein recognition and interaction. The docking energies of the mutant complex and the native complex were compared to see the effects of the mutations in the Modulatory regions. Mutations of Modulatory residues in high-activity RGS proteins lead to loss of function, whereas multiple mutations in the low-activity RGS proteins in critical Modulatory positions lead to complete gain of function. In the RGS proteins the Significant and Conserved core residues with peripheral Modulatory residues selectively optimize G protein recognition and inactivation. The flexibility of the structures of the mutant complexes were seen to be higher and the accessible surface area for the complexes increased after the mutations in the Modulatory residues. Through this approach we analyzed the interaction specificity among the RGS and the G alpha protein, the approach can also be applied to other protein families to find the residues which along with the core binding domain, fine tune the protein recognition and are crucial in the loss or gain of function.
authors.affiliation: Bioinformatics Division, School of Bio Sciences and Technology (SBST), Vellore Institute of Technology University, Vellore, 632014, Tamil Nadu, India.
authors.forename: Gavish
authors.initials: G
authors.lastname: Gulati
authors.forename: Krutika Satish
authors.initials: KS
authors.lastname: Gaonkar
authors.forename: Balu
authors.initials: B
authors.lastname: Kamraj
authors.forename: Ambuj
authors.initials: A
authors.lastname: Kumar
authors.forename: Rituraj
authors.initials: R
authors.lastname: Purohit
mesh_terms: D019204:GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020690:GTPase-Activating Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020710:RGS Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D020690:GTPase-Activating Proteins; D020710:RGS Proteins; D019204:GTP-Binding Proteins