Geranylgeranyl diphosphate (GGPP) synthase from Thermus thermophilus HB8 was expressed in Escherichia coli, purified to homogeneity and crystallized both as the recombinant native protein and its selenomethionine (SeMet) derivative. Well diffracting crystals of these proteins were obtained belonging to the tetragonal space group P4(1) or P4(3), with unit-cell parameters a = b = 139.88, c = 73.37 A. There were two homodimers in the asymmetric unit. A native data set was collected to 1.55 A resolution and a data set suitable for MAD phasing was collected to 2.40 A resolution on beamline BL40B2 at SPring-8.
Fibrosis, characterised by excessive extracellular matrix deposition, contributes to both organ failure and significant mortality worldwide. Whereas fibroblasts are activated into myofibroblasts, marked by phenotypic factors such as α-smooth muscle actin (α-SMA), periostin, fibroblast activation protein (FAP) and heat shock protein 47 (HSP47), the cellular processes of trans-differentiation for fibrosis development remain poorly understood. Herein, we hypothesised that the molecular signalling of geranylgeranyl pyrophosphate (GGPP), a crucial biochemical molecule for protein prenylation, is essential in the regulation of profibrotic mechanisms for fibroblast-to-myofibroblast activation.
Background: Neutropenia is more common in patients with systemic lupus erythematosus (SLE) and is a major cause of life-threatening infections. The increased apoptosis of neutrophils is likely to be an essential cause of neutropenia in SLE. However, the detailed mechanisms of increased neutrophil apoptosis in SLE remain unknown.
Nitrogen bisphosphonates, such as zoledronic acid, target the enzyme farnesyl diphosphate synthase (FDPS) in the isoprenoid biosynthetic pathway (IBP), and are the frontline treatment for osteolytic bone diseases. A strong affinity of these agents for bone limits their distribution out of the skeleton. Geranylgeranyl diphosphate synthase (GGDPS) is directly downstream to FDPS in the IBP and novel GGDPS inhibitors such as RAM2061 have been shown to have key drug-like features including prolonged half-life, metabolic stability, and systemic distribution.
Despite several studies documenting secondary metabolite (SM) production by endophytes, their commercial use is often limited owing to the research lacunae in the underlying biosynthetic pathway and the corresponding metabolic flux. Combining epigenetic modulation with RNA-Seq analysis constitutes a promising approach for inducing regulatory gene(s) and thereby identifying their role in SM biosynthesis. Our earlier studies had identified the hypomethylating effects of prednisone in umbelliferone (UMB) (7-hydroxyl coumarin) producing endophytic Fusarium oxysporum isolate, ZzEF8 isolated from Zingiber zerumbet rhizomes.
An unusual family of bifunctional terpene synthases has been discovered in which both catalytic domains - a prenyltransferase and a cyclase - are connected by a long, flexible linker. These enzymes are unique to fungi and catalyze the first committed steps in the biosynthesis of complex terpenoid natural products: the prenyltransferase assembles 5-carbon precursors to form C geranylgeranyl diphosphate (GGPP), and the cyclase converts GGPP into a polycyclic hydrocarbon product. Weak domain-domain interactions as well as linker flexibility render these enzymes refractory to crystallization and challenge their visualization by cryo-EM.
