The SH2 domain of cytoplasmic tyrosine kinases can enhance catalytic activity and substrate recognition, but the molecular mechanisms by which this is achieved are poorly understood. We have solved the structure of the prototypic SH2-kinase unit of the human Fes tyrosine kinase, which appears specialized for positive signaling. In its active conformation, the SH2 domain tightly interacts with t...

Group II introns are self-splicing ribozymes that catalyze their own excision from precursor transcripts and insertion into new genetic locations. Here we report the crystal structure of an intact, self-spliced group II intron from Oceanobacillus iheyensis at 3.1 angstrom resolution. An extensive network of tertiary interactions facilitates the ordered packing of intron subdomains around a ribo...

Over the last decades, tremendous progress has been made in the control of catalytic materials on the nanometer size scale. This includes tailoring of pore sizes of catalytic materials by different soft and hard templating techniques, size control of catalytically active metal particles by solution phase synthesis of such particles and subsequent deposition on supports, the placement of catalyt...

It is a commonly held belief that a consistent dimensional reduction ansatz can be equally well substituted into either the higher-dimensional equations of motion or the higherdimensional action, and that the resulting lower-dimensional theories will be the same. This is certainly true for Kaluza-Klein circle reductions and for DeWitt group-manifold reductions, where group-invariance arguments ...

Lytic transglycosylases are abundant peptidoglycan lysing enzymes that degrade the heteropolymers of bacterial cell walls in metabolic processes or in the course of a bacteriophage infection. The conventional catalytic mechanism of transglycosylases involves only the Glu or Asp residue. Endolysin gp144 of Pseudomonas aeruginosa bacteriophage phiKZ belongs to the family of Gram-negative transgly...

This review chronicles the synergistic growth of the fields of fatty acid and polyketide synthesis over the last century. In both animal fatty acid synthases and modular polyketide synthases, similar catalytic elements are covalently linked in the same order in megasynthases. Whereas in fatty acid synthases the basic elements of the design remain immutable, guaranteeing the faithful production ...

We present an efficient method of introducing fluorophore labels at selected locations in a large RNA. The method is based on specific and highly efficient hybridization between a fluorophore-containing DNA oligonucleotide and a modular hairpin loop replacing a functionally unimportant hairpin loop in the RNA. We demonstrate its feasibility using a 255-nucleotide RNA derived from the catalytic ...

Homoserine O-acetyltransferase (HTA, EC 2.3.1.31) initiates methionine biosynthesis pathway by catalyzing the transfer of acetyl group from acetyl-CoA to homoserine. This study reports the crystal structure of HTA from Leptospira interrogans determined at 2.2A resolution using selenomethionyl single-wavelength anomalous diffraction method. HTA is modular and consists of two structurally distinc...