Agrobacterium radiobacter K84, used worldwide to biocontrol crown gall disease caused by Agrobacterium tumefaciens, produces an antiagrobacterial compound called agrocin 84. We report the nucleotide sequence of pAgK84, a 44.42-kb plasmid coding for production of this disubstituted adenine nucleotide antibiotic. pAgK84 encodes 36 ORFs, 17 of which (agn) code for synthesis of or immunity to agrocin 84. Two genes, agnB2 and agnA, encode aminoacyl tRNA synthetase homologues. We have shown that the toxic moiety of agrocin 84 inhibits cellular leucyl-tRNA synthetases and AgnB2, which confers immunity to the antibiotic, is a resistant form of this enzyme. AgnA, a truncated homologue of asparaginyl tRNA synthetase could catalyze the phosphoramidate bond between a precursor of the methyl pentanamide side group and the nucleotide. We propose previously undescribed chemistry, catalyzed by AgnB1, to generate the precursor necessary for this phosphoramidate linkage. AgnC7 is related to ribonucleotide reductases and could generate the 3 -deoxyarabinose moiety of the nucleoside. Bioinformatics suggest that agnC3, agnC4, and agnC6 contribute to maturation of the methyl pentanamide, whereas agnC2 may produce the glucofuranose side group bound to the adenine ring. AgnG is related to bacterial exporters. An agnG mutant accumulated agrocin 84 intracellularly but did not export the antibiotic. pAgK84 is transmissible and encodes genes for conjugative DNA processing but lacks a type IV secretion system, suggesting that pAgK84 transfers by mobilization. By sequence analysis, the deletion engineered into pAgK1026 removed the oriT and essential tra genes, confirming the enhanced environmental safety of this modified form of pAgK84.Agrobacterium radiobacter ͉ biological control ͉ pAgK84

The gene encoding a novel modular xylanase from Cellulosimicrobium sp. strain HY-13 was identified and expressed in Escherichia coli, and its truncated gene product was characterized. The enzyme consisted of three distinct functional domains, an N-terminal catalytic GH10 domain, a fibronectin type 3 domain, and C-terminal carbohydrate-binding module 2.

Abstract-The peroxisome proliferator-activated receptor (PPAR)␦ has been implicated in the pathogenesis of atherogenic disorders. However, its physiological roles and functions in vascular smooth muscle cells (VSMCs) remain relatively unclear. In the present study, we show that the gene encoding transforming growth factor (TGF)-␤1 is a PPAR␦ target in VSMCs. The PPAR␦ activator GW501516 upregulates TGF-␤1 expression in a dose-and time-dependent manner. This induction is attenuated significantly by the presence of small interfering RNA against PPAR␦ or GW9662, an inhibitor of PPAR␦. Furthermore, activated PPAR␦ induces TGF-␤1 promoter activity by binding to the direct repeat-1 response element TGF-␤1-direct repeat-1. Mutations in the 5Ј or 3Ј half-sites of the response element totally abrogate transcriptional activation and PPAR␦ binding, which suggests that this site is a novel type of PPAR␦ response element. In addition, ligand-activated PPAR␦ attenuated the promoter activity and expression of monocyte chemoattractant protein-1 induced by interleukin-1␤. These effects were significantly reduced in the presence of small interfering RNA against PPAR␦, anti-TGF-␤1 antibody, or a TGF-␤ type I receptor inhibitor. Decreased monocyte chemoattractant protein-1 expression induced by PPAR␦ was mediated by the effector of TGF-␤1, Smad3. Finally, administration of GW501516 to mice upregulated TGF-␤1, whereas the expression of proinflammatory genes including monocyte chemoattractant protein-1 was significantly attenuated in the thoracic aorta. Taken

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