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Tobacco plants were genetically engineered to express a detoxifying pathway for the herbicide phenmedipham. A gene fromArthrobacter oxidans strain P52 that encodes an enzyme catalysing the hydrolytic cleavage of the carbamate compound phenmedipham has recently been cloned and sequenced. The coding sequence was fused with a cauliflower mosaic virus 35S promoter and introduced into tobacco plants byAgrobacterium-mediated gene transfer. Transgenic plants expressing high levels of phenmedipham hydrolase exhibited resistance when sprayed with the herbicide at up to ten times the usual field application rate.

The rhizocticines and plumbemicines are two groups of di- and tripeptid antibiotics thought to interfere with threonine or threonine-related metabolism. Z-2-amino-5-phosphono-3-pentenoic acid, the common unusual amino acid constituent of the rhizocticines and plumbemicines, was found to irreversibly inhibit Escherichia coli threonine synthase in a time-dependent reaction that followed pseudo-first order and saturation kinetics. These data provide evidence that the toxicity of the rhizocticines and plumbemicines is due to the inhibition of threonine synthase by Z-2-amino-5-phosphone-3-pentenoic acid, which is liberated by peptidases after uptake into the target cell. Additionally, methods for the purification of threonine synthase from an overproducing E. coli strain and for the enzymatic synthesis of l-homoserine phosphate are described.

Cystathionine β-lyase (CBL) is a member of the γ-family of PLP-dependent enzymes, that cleaves Cβ-S bonds of a broad variety of substrates. The crystal structure of CBL fromE. colihas been solved using MIR phases in combination with density modification. The structure has been refined to anR-factor of 15.2% at 1.83 Å resolution using synchroton radiation diffraction data. The asymmetric unit of the crystal cell (space group C222₁) contains two monomers related by 2-fold symmetry. A homotetramer with 222 symmetry is built up by crystallographic and non-crystallographic symmetry. Each monomer of CBL can be described in terms of three spatially and functionally different domains. The N-terminal domain (residues 1 to 60) consists of three α-helices and one β-strand. It contributes to tetramer formation and is part of the active site of the adjacent subunit. The second domain (residues 61 to 256) harbors PLP and has an α/β-structure with a seven-stranded β-sheet as the central part. The remaining C-terminal domain (residues 257 to 395), connected by a long α-helix to the PLP-binding domain, consists of four helices packed on the solvent-accessible side of an antiparallel four-stranded β-sheet. The fold of the C-terminal and the PLP-binding domain and the location of the active site are similar to aminotransferases. Most of the residues in the active site are strongly conserved among the enzymes of the transsulfuration pathway. Additionally, CBL is homologous to themalYgene product indicating an evolutionary relationship between α and γ-family of PLP-dependent enzymes. The structure of the β,β,β-trifluoroalanine inactivated CBL has been refined at 2.3 Å resolution to anR-factor of 16.2%. It suggests that Lys210, the PLP-binding residue, mediates the proton transfer between C^αand S^γ.

The metCgene coding for cystathionine β-lyase of Escherichia colihas been cloned and used to construct an overproducing E. colistrain. An efficient purification scheme has been developed and the purified enzyme has been crystallized by the hanging drop vapour diffusion method using either ammonium sulfate or polyethyleneglycol 400 as precipitating agent. The crystals belong to the orthorombic space group C222 1. Their unit cell parameters are a = 60.9 Å, b = 154.7 Åandc = 152.7 Å. Consideration of the possible values of VMaccounts for the presence of one dimer per asymmetric unit. The crystals are suitable for X-ray analysis and a complete native date set to 1.83 Å resolution has been collected using synchrotron radiation.

The metCgene coding for cystathionine β‐lyase of Escherichia colihas been cloned and used to construct an overproducing E. colistrain. An efficient purification scheme has been developed and the purified enzyme has been crystallized by the hanging drop vapour diffusion method using either ammonium sulfate or polyethyleneglycol 400 as precipitating agent. The crystals belong to the orthorombic space group C2221. Their unit cell parameters are . Consideration of the possible values of VMaccounts for the presence of one dimer per asymmetric unit. The crystals are suitable for X‐ray analysis and a complete native date set to 1.83 Å resolution has been collected using synchrotron radiation.

Summary: We have created PhenomicDB, a multi-species genotype/phenotype database by merging public genotype/phenotype data from a wide range of model organisms and Homo sapiens. Until now these data were available in distinct organism-specific databases (e.g. WormBase, OMIM, FlyBase and MGI). We compiled this wealth of data into a single integrated resource by coarse-grained semantic mapping of the phenotypic data fields, by including common gene indices (NCBI Gene), and by the use of associated orthology relationships. With its use-case-oriented user interface, PhenomicDB allows scientists to compare and browse known phenotypes for a given gene or a set of genes from different organisms simultaneously. Availability: PhenomicDB has been implemented at Schering AG as described below. A PhenomicDB implementation differing in some technical details has been set up for the public at Metalife AG http://www.phenomicDB.de Contact: bertram.weiss@schering.de Supplementary information: database model, semantic mapping table.

The series of studies on the human K light chain genes of the various subgroups is concluded by this report on the isolation and nucleotide sequence determination of a functional VKIV gene (abbreviations ref. 1) and its germline counterpart. The rearranged gene which stems from a lymphoid cell line and the germline gene differ in four nucleotides which can be attributed to somatic mutations; three of the mutations are clustered in CDR3. The germline gene regions of two unrelated individuals were identical over a stretch of 1267 bp. By hybridization experiments it is shown that the human K locus contains only one VKIV gene. In 16 lymphoid cell lines studied here, the VKIV gene is frequently deleted or aberrantly rearranged which may be a consequence of peculiarities of its function and/or Its structural organization.