By using a bioinformatics screen of the Escherichia coli genome for potential molybdenum-containing enzymes, we have identified a novel oxidoreductase conserved in the majority of Gram-negative bacteria. The identified operon encodes for a proposed heterodimer, YedYZ in Escherichia coli, consisting of a soluble catalytic subunit termed YedY, which is likely anchored to the membrane by a heme-co...

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine. In addition to its known receptor-mediated biological activities, MIF possesses a catalytic site of unknown function between subunits of a homotrimer. Each subunit contributes three β-strands to adjacent subunits to form a core seven-stranded β-sheet for each monomer. MIF monomers, dimers, or trimers have been reported,...

Purified preparations of a distinct autophosphorylation-activated protein kinase from bovine kidney phosphorylated and inactivated purified preparations of protein phosphatase 2A2 (PP2A2) by about 80% with the autophosphorylation-activated protein kinase, protamine kinase, and 32P-labeled myelin basic protein as substrates. Analysis of incubations performed in the presence of 0.2 mM [gamma-32P]...

Crystals of the catalytic chain of Methanococcus jannaschii aspartate transcarbamoylase (ATCase) grew in the presence of the regulatory chain in the hexagonal space group P6(3)22, with one monomer per asymmetric unit. This is the first time that crystals with only one monomer in the asymmetric unit have been obtained; all known structures of the catalytic subunit contain several crystallographi...

The catalytic subunit of aspartate transcarbamoylase from Escherichia coli reacts readily with 2,4,6-trinitrobenzenesulfonate, resulting in the loss of enzymatic activity. Substrates and substrate analogs protect the enzyme in a competitive manner, indicating that the loss of activity is due to modification of active-site residues. This conclusion was confirmed by fractionating tryptic digests ...

BACKGROUND The P-type ATPase family constitutes a collection of ion pumps that form phosphorylated intermediates during ion transport. One of the best known members of this family is the Na⁺,K⁺-ATPase. The catalytic subunit of the Na⁺,K⁺-ATPase includes several functional domains that determine its enzymatic and trafficking properties. METHODOLOGY/PRINCIPAL FINDINGS Using the yeast two-hybrid...

The form of protein phosphatase-1 associated with hepatic glycogen (PP1G) was purified to near homogeneity from rat liver by affinity chromatography on microcystin-Sepharose and gel-filtration. The enzyme is a heterodimer consisting of the catalytic subunit of PP1 (the alpha and beta isoforms) complexed to a 33 kDa glycogen-binding (GL) subunit. The GL subunit binds phosphorylase a with high af...