Assembly of the elongated collagen prolyl 4-hydroxylase αβ heterotetramer around a central α dimer.

Collagen prolyl 4-hydroxylase (C-P4H), an αβ heterotetramer, is a crucial enzyme for collagen synthesis. The α-subunit consists of an N-terminal dimerization domain, a central peptide substrate-binding (PSB) domain, and a C-terminal catalytic (CAT) domain. The β-subunit [also known as protein disulfide isomerase (PDI)] acts as a chaperone, stabilizing the functional conformation of C-P4H.

Directed evolution of Tau class glutathione transferases reveals a site that regulates catalytic efficiency and masks co-operativity.

A library of Tau class GSTs (glutathione transferases) was constructed by DNA shuffling using the DNA encoding the Glycine max GSTs GmGSTU2-2, GmGSTU4-4 and GmGSTU10-10. The parental GSTs are >88% identical at the sequence level; however, their specificity varies towards different substrates. The DNA library contained chimaeric structures of alternated segments of the parental sequences and point mutations.

A glutathione transferase from Agrobacterium tumefaciens reveals a novel class of bacterial GST superfamily.

In the present work, we report a novel class of glutathione transferases (GSTs) originated from the pathogenic soil bacterium Agrobacterium tumefaciens C58, with structural and catalytic properties not observed previously in prokaryotic and eukaryotic GST isoenzymes. A GST-like sequence from A. tumefaciens C58 (Atu3701) with low similarity to other characterized GST family of enzymes was identified.

Expression, purification and crystallization of Chaetomium thermophilum Cu,Zn superoxide dismutase.

Cu,Zn superoxide dismutase (Cu,ZnSOD) from the thermophilic fungus Chaetomium thermophilum was expressed in Pichia pastoris and purified. Crystals were grown in over 120 conditions but only those produced with 1.4 M sodium potassium phosphate pH 8.

Structure of Helicobacter pylori L-asparaginase at 1.4 A resolution.

Bacterial L-asparaginases have been used in the treatment of childhood acute lymphoblastic leukaemia for over 30 years. Their therapeutic effect is based on their ability to catalyze the conversion of L-asparagine, an essential amino acid in certain tumours, to L-aspartic acid and ammonia. Two L-asparaginases, one from Escherichia coli and the other from Erwinia chrysanthemi, have been widely employed in clinical practice as anti-leukaemia drugs.

Investigation of the role of conserved residues Ser13, Asn48 and Pro49 in the catalytic mechanism of the tau class glutathione transferase from Glycine max.

Plant glutathione transferases (GSTs) play a key role in the metabolism of various xenobiotics. In this report, the catalytic mechanism of the tau class GSTU4-4 isoenzyme from Glycine max (GmGSTU4-4) was investigated by site-directed mutagenesis and steady-state kinetic analysis. The catalytic properties of the wild-type enzyme and three mutants of strictly conserved residues (Ser13Ala, Asn48Ala and Pro49Ala) were studied in 1-chloro-2,4-dinitrobenzene (CDNB) conjugation reaction.

Crystal structure of Glycine max glutathione transferase in complex with glutathione: investigation of the mechanism operating by the Tau class glutathione transferases.

Cytosolic GSTs (glutathione transferases) are a multifunctional group of enzymes widely distributed in Nature and involved in cellular detoxification processes. The three-dimensional structure of GmGSTU4-4 (Glycine max GST Tau 4-4) complexed with GSH was determined by the molecular replacement method at 2.7 A (1 A=0.

Crystallographic and functional characterization of the fluorodifen-inducible glutathione transferase from Glycine max reveals an active site topography suited for diphenylether herbicides and a novel L-site.

Glutathione transferases (GSTs) from the tau class (GSTU) are unique to plants and have important roles in stress tolerance and the detoxification of herbicides in crops and weeds. A fluorodifen-induced GST isoezyme (GmGSTU4-4) belonging to the tau class was purified from Glycine max by affinity chromatography. This isoenzyme was cloned and expressed in Escherichia coli, and its structural and catalytic properties were investigated.

Expression, purification and crystallization of Helicobacter pylori L-asparaginase.

The L-asparaginases from Escherichia coli and Erwinia chrysanthemi are effective drugs that have been used in the treatment of acute childhood lymphoblastic leukaemia for over 30 years. However, despite their therapeutic potential, they can cause serious side effects as a consequence of their intrinsic glutaminase activity, which leads to L-glutamine depletion in the blood. Consequently, new asparaginases with low glutaminase activity, fewer side effects and high activity towards L-asparagine are highly desirable as better alternatives in cancer therapy.