Rational protein engineering in action: the first crystal structure of a phenylalanine tRNA synthetase from Staphylococcus haemolyticus.

In this article, we describe for the first time the high-resolution crystal structure of a phenylalanine tRNA synthetase from the pathogenic bacterium Staphylococcus haemolyticus. We demonstrate the subtle yet important structural differences between this enzyme and the previously described Thermus thermophilus ortholog. We also explain the structure-activity relationship of several recently reported inhibitors.

The structure of the carboxyltransferase component of acetyl-coA carboxylase reveals a zinc-binding motif unique to the bacterial enzyme.

Acetyl-coA carboxylase (ACC) is a central metabolic enzyme that catalyzes the committed step in fatty acid biosynthesis: biotin-dependent conversion of acetyl-coA to malonyl-coA. The bacterial carboxyltransferase (CT) subunit of ACC is a target for the design of novel therapeutics that combat severe, hospital-acquired infections resistant to the established classes of frontline antimicrobials. Here, we present the structures of the bacterial CT subunits from two prevalent nosocomial pathogens, Staphylococcus aureus and Escherichia coli, at a resolution of 2.

Two distinct classes of CCAAT box elements that bind nuclear factor-Y/alpha-actinin-4: potential role in human CYP1A1 regulation.

A negative regulatory element (NRE1; position -794 to -774) was previously identified that mediates the downregulation of CYP1A1, including partial suppression of Ah receptor-dependent induction. The CCAAT-box binding protein, nuclear factor-Y (NF-Y), is a component of one of two protein complexes that specifically and competitively bind the CYP1A1 NRE1 in vitro with nearly equal affinity. The second complex involves an unidentified protein(s) called the negative regulatory factor (NRF).

Enzymatic removal of selected aromatic contaminants from wastewater by a fungal peroxidase from Coprinus macrorhizus in batch reactors.

The use of enzymes such as horseradish peroxidase (HRP) for degrading or removing toxic organics from synthetic wastewater has been demonstrated previously. Potential alternatives to HRP are other peroxidases, various ligninases, haloperoxidases and laccases. Results of this study indicate that a fungal peroxidase from Coprinus macrorhizus (CMP) has the capability to catalyze the same reactions as HRP.

Multifunctional activities of pickerel liver alcohol dehydrogenase.

A major isozyme of pickerel liver alcohol dehydrogenase has been purified to homogeneity. The enzyme, in addition to catalyze NAD(P)(+)-linked dehydrogenation of alcohols, also mediates dismutation of aldehydes and hydrolysis of esters. Steady-state kinetic studies and chemical modifications of the pickerel liver enzyme with respect to its esterolytic and dismutative activities were carried out.