Structural studies of the dual-substrate TIM-barrel phosphoribosyl isomerase A
نویسندگان
چکیده
24 European Crystallographic Meeting, ECM24, Marrakech, 2007 Page s126 Acta Cryst. (2007). A63, s126 Escherichia coli beta-galactosidase is known to be active only in the form of tetramers, while the cold-active Arthrobacter sp. C2-2 beta-galactosidase forms compact hexamers with active sites oriented into an internal cavity, connected by three types of channels with exterior solvent. Additionally, sequence differences between both enzymes exist in the active site. Acknowledgement: The research was supported by the Grant Agency of the Czech Republic (project 204/02/0843/A) and by the Grant Agency of the Academy of Sciences of the Czech Republic (project B500500512).
منابع مشابه
CGTase cyclodextrin glycosyltransferase HisA ProFAR isomerase HisF imidazole glycerol phosphate synthase TIM triosephosphate isomerase TrpC indole glycerol phosphate synthase TrpF phosphoribosylanthranilate isomerase
The (βα)8-barrel is a versatile single-domain protein fold that is adopted by a large number of enzymes. The (βα)8-barrel fold has been used as a model to elucidate the structural basis of protein thermostability and in studies to interconvert catalytic activities or substrate specificities by rational design or directed evolution. Recently, the (βα)4-half-barrel was identified as a possible st...
متن کاملA monomeric TIM-barrel structure from Pyrococcus furiosus is optimized for extreme temperatures.
The structure of phosphoribosyl anthranilate isomerase (TrpF) from the hyperthermophilic archaeon Pyrococcus furiosus (PfTrpF) has been determined at 1.75 Å resolution. The PfTrpF structure has a monomeric TIM-barrel fold which differs from the dimeric structures of two other known thermophilic TrpF proteins. A comparison of the PfTrpF structure with the two known bacterial thermophilic TrpF st...
متن کاملEndoglucanase activity at a second site in Pyrococcus furiosus triosephosphate isomerase—Promiscuity or compensation for a metabolic handicap?
The eight-stranded (β/α)8 barrel fold known as the Triosephosphate isomerase (TIM) barrel is the most commonly observed fold in enzymes, displaying an eightfold structural symmetry. The sequences and structures of different TIM barrel enzymes suggest that nature exploits the modularity inherent in the eightfold symmetry to generate enzymes with diverse enzymatic activities and, in certain cases...
متن کاملDirected evolution of a (ba)8-barrel enzyme to catalyze related reactions in two different metabolic pathways
Enzymes participating in different metabolic pathways often have similar catalytic mechanisms and structures, suggesting their evolution from a common ancestral precursor enzyme. We sought to create a precursor-like enzyme for N*-[(5*-phosphoribosyl)formimino]-5-aminoimidazole-4-carboxamide ribonucleotide (ProFAR) isomerase (HisA; EC 5.3.1.16) and phosphoribosylanthranilate (PRA) isomerase (Trp...
متن کاملHidden Sequence Repeats: Additional Evidence for the Origin of TIM-Barrel Family
Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from duplication. As one of the six popular folds (super-folds) possessing an approximate structural symmetry, the triosephosphate isomerase barrel (TIM-barrel) domain has been widely studie...
متن کامل