1JAD

C-terminal Domain of Turkey PLC-beta

Summary for 1JAD

• Entry DOI: 10.2210/pdb1jad/pdb
• Descriptor: phospholipase C beta, SULFATE ION (3 entities in total)
• Functional Keywords: alpha helical coiled coil, hydrolase
• Biological source: Meleagris gallopavo (turkey)
• Total number of polymer chains: 2
• Total formula weight: 59776.24

Authors

Singer, A.U.,Waldo, G.L.,Harden, T.K.,Sondek, J. (deposition date: 2001-05-30, release date: 2001-12-28, Last modification date: 2024-10-30)

Primary citation

Singer, A.U.,Waldo, G.L.,Harden, T.K.,Sondek, J.
A unique fold of phospholipase C-beta mediates dimerization and interaction with G alpha q.
Nat.Struct.Biol., 9:32-36, 2002

PubMed Abstract: GTP-bound subunits of the Gq family of G alpha subunits directly activate phospholipase C-beta (PLC-beta) isozymes to produce the second messengers inositol 1,4,5-trisphosphate and diacylglycerol. PLC-betas are GTPase activating proteins (GAPs) that also promote the formation of GDP-bound, inactive G beta subunits. Both phospholipase activation by G alpha-GTP subunits and GAP activity require a C-terminal region unique to PLC-beta isozymes. The crystal structure of the C-terminal region from an avian PLC-beta, determined at 2.4 A resolution, reveals a novel fold composed almost entirely of three long helices forming a coiled-coil that dimerizes along its long axis in an antiparallel orientation. The dimer interface is extensive ( approximately 3,200 A(2)), and, based on gel exclusion chromatography, full length PLC-betas are dimeric, indicating that PLC-betas likely function as dimers. Sequence conservation, mutational data and molecular modeling show that an electrostatically positive surface of the dimer contains the major determinants for binding G beta q. Effector dimerization, as highlighted by PLC-betas, provides a viable mechanism for regulating signaling cascades linked to heterotrimeric G proteins.

PubMed: 11753430
DOI: 10.1038/nsb731

Experimental method

X-RAY DIFFRACTION (2.4 Å)