GTP-binding protein

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Contents

Function

GTP-binding proteins or G proteins are transmitting signals outside the cell which cause changes within the cell. They act as molecular switches which are on when binding GTP and off when binding GDP. GTP-binding proteins belong to two families: heterotrimeric G proteins[1] see Transducin and small GTPases[2].

  • Small GTPase structure is homologous to that of the α subunit of heterotrimeric G protein. See details on small GTP-binding protein LepA in LepA.
  • Nucleolar GTP-binding proteins are involved in the biogenesis of ribosome[3].
  • Heterotrimeric G protein or guanine nucleotide-binding protein or G protein (GNBP) are heterodimeric membrane proteins composed of α, β and γ subunits. GNBP is involved in mammalian cellular signaling pathways. GNBP α subunit binds GDP or GTP. When bound to GTP it dissociates from the β and γ subunits, binds to adenylate cyclase which converts ATP to cAMP. See also

G protein-coupled receptor
Beta2 adrenergic receptor-Gs protein complex updated
Dedicator of cytokinesis protein

Disease

Mutations in heterotrimeric G protein α subunit were identified in endocrine tumors and in McCune-Albright syndrome[4].

Relevance

Rho-related small GTP-binding protein is inhibited by the antifungal drug Cancidas[5].

Structural highlights

E. coli small GTPase ERA binds GDP in a cavity formed by 7 highly conserved regions G1, G4, G5[6]. GDP binding site. Water molecules are shown as red spheres.

3D Structures of GTP-binding protein

GTP-binding protein 3D structures


E. coli small GTP-binding protein ERA complex with GDP and sulfate (PDB code 3ieu)

Drag the structure with the mouse to rotate


See Also

References

  1. ↑ Preininger AM, Hamm HE. G protein signaling: insights from new structures. Sci STKE. 2004 Jan 27;2004(218):re3. PMID:14762218 doi:http://dx.doi.org/10.1126/stke.2182004re3
  2. ↑ Takai Y, Sasaki T, Matozaki T. Small GTP-binding proteins. Physiol Rev. 2001 Jan;81(1):153-208. PMID:11152757
  3. ↑ Kim YI, Bandyopadhyay J, Cho I, Lee J, Park DH, Cho JH. Nucleolar GTPase NOG-1 regulates development, fat storage, and longevity through insulin/IGF signaling in C. elegans. Mol Cells. 2014 Jan;37(1):51-7. PMID:24552710 doi:10.14348/molcells.2014.2251
  4. ↑ Lania A, Mantovani G, Spada A. G protein mutations in endocrine diseases. Eur J Endocrinol. 2001 Nov;145(5):543-59. PMID:11720871
  5. ↑ Moreno-Velasquez SD, Seidel C, Juvvadi PR, Steinbach WJ, Read ND. Caspofungin-Mediated Growth Inhibition and Paradoxical Growth in Aspergillus fumigatus Involve Fungicidal Hyphal Tip Lysis Coupled with Regenerative Intrahyphal Growth and Dynamic Changes in beta-1,3-Glucan Synthase Localization. Antimicrob Agents Chemother. 2017 Sep 22;61(10). pii: AAC.00710-17. doi:, 10.1128/AAC.00710-17. Print 2017 Oct. PMID:28760907 doi:http://dx.doi.org/10.1128/AAC.00710-17
  6. ↑ Tu C, Zhou X, Tropea JE, Austin BP, Waugh DS, Court DL, Ji X. Structure of ERA in complex with the 3' end of 16S rRNA: implications for ribosome biogenesis. Proc Natl Acad Sci U S A. 2009 Sep 1;106(35):14843-8. Epub 2009 Aug 17. PMID:19706445
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