1dce
From Proteopedia
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CRYSTAL STRUCTURE OF RAB GERANYLGERANYLTRANSFERASE FROM RAT BRAIN
Overview
BACKGROUND: Rab geranylgeranyltransferase (RabGGT) catalyzes the addition, of two geranylgeranyl groups to the C-terminal cysteine residues of Rab, proteins, which is crucial for membrane association and function of these, proteins in intracellular vesicular trafficking. Unlike protein, farnesyltransferase (FT) and type I geranylgeranyltransferase, which both, prenylate monomeric small G proteins or short peptides, RabGGT can, prenylate Rab only when Rab is in a complex with Rab escort protein (REP)., RESULTS: The crystal structure of rat RabGGT at 2.0 A resolution reveals, an assembly of four distinct structural modules. The beta subunit forms an, alpha-alpha barrel that contains most of the residues in the active site., The alpha subunit consists of a helical domain, an immunoglobulin, (Ig)-like domain, and a leucine-rich repeat (LRR) domain. The N-terminal, region of the alpha subunit binds to the active site in the beta subunit;, residue His2alpha directly coordinates a zinc ion. The prenyl-binding, pocket of RabGGT is deeper than that in FT. CONCLUSIONS: LRR and Ig, domains are often involved in protein-protein interactions; in RabGGT they, might participate in the recognition and binding of REP. The binding of, the N-terminal peptide of the alpha subunit to the active site suggests an, autoinhibition mechanism that might contribute to the inability of RabGGT, to recognize short peptides or Rab alone as its substrate. Replacement of, residues Trp102beta and Tyr154beta in FT by Ser48beta and Leu99beta, respectively, in RabGGT largely determine the different lipid-binding, specificities of the two enzymes.
About this Structure
1DCE is a Protein complex structure of sequences from Rattus norvegicus with ZN as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of Rab geranylgeranyltransferase at 2.0 A resolution., Zhang H, Seabra MC, Deisenhofer J, Structure. 2000 Mar 15;8(3):241-51. PMID:10745007
Page seeded by OCA on Tue Nov 20 13:10:03 2007
