Crystallization and preliminary X-ray analysis of the formiminotransferase domain from the bifunctional enzyme formiminotransferase–cyclodeaminase

Abstract

) is a bifunctional enzyme involved in the histidine-degradation pathway which exhibits speci®city for polyglutamylated folate substrates. The ®rst function of the enzyme transfers the formimino group of formiminoglutamate to the N 5 position of tetrahydrofolate, while the second function catalyses the cyclodeamination of the formimino group, yielding N 5,10 -methenyl-tetrahydrofolate, with ef®cient channeling of the intermediate between these activities. Initial studies have shown that the enzyme consists of eight identical subunits of 62 kDa each, arranged as a circular tetramer of dimers. It is this formation which results in two different dimeric interfaces, which are necessary for the two different activities. The identical subunits have been shown to consist of two domains, each of which can be obtained as dimers. The formiminotransferase domain has been crystallized in the presence of the substrate analogue folinic acid. The crystals belong to space group P2 1 2 1 2 1 , with unit-cell dimensions a = 64.4, b = 103.7, c = 122.3 A Ê . Both a native data set and a mercurial derivative data set have been collected to 2.8 A Ê resolution.

Multifactorial Comparative Proteomic Study of Cytochrome P450 2E1 Function in Chronic Alcohol Administration

“…It catalyzes one-carbon units transfer from formiminoglutamate, a metabolite in the histidine degradation pathway, to tetrahydrofolate, reversibly as well as catalyzes deamination of 5-formimidoyltetrahydrofolate. FTCD is also a liver-specific autoantigen in patients with autoimmune hepatitis [41], [42]. It was identified in a proteomic study as being down-regulated in hepatocellular carcinoma (HCC) [43].…”

The crystal structure of the formiminotransferase domain of formiminotransferase-cyclodeaminase: implications for substrate channeling in a bifunctional enzyme

“…Overexpressed hexahistidine-tagged FT domain was produced and purified as described previously [14] omitting the last DEAE sepharose column. Crystals were obtained as described elsewhere [22]. Briefly, crystals of the FT domain were grown by the hanging-drop method using 1 M citrate, 100 mM Tris pH 8.0 and 10% (v/v) glycerol as the precipitant.…”

Comparative folate metabolism in humans and malaria parasites (part II): activities as yet untargeted or specific to Plasmodium

“…Thus, the role of this part of the pathway is to provide an additional source of such groups. The 3D structure of this enzyme complex has been resolved [10,11]; however, so far, no studies have been devoted to the screening of GFT or FCD inhibitors. It could be that the malaria parasite does not require the extra capacity to provide C1 groups that this complex provides because no gene from any of the Plasmodium databases is identified in BLAST searches using either bacterial or vertebrate GFT–FCD probes.…”