SCO6992, a Protein with β-Glucuronidase Activity, Complements a Mutation at the Locus and Promotes Antibiotic Biosynthesis in .

is a filamentous soil bacterium producing several kinds of antibiotics. abs8752 is an (antibiotic synthesis deficient)-type mutation at the locus; it is characterized by an incapacity to produce any of the four antibiotics synthesized by its parental strain J1501. A chromosomal DNA fragment from J1501, capable of complementing the phenotype of the abs8752 mutant, was cloned and analyzed.

Phase transition and critical dynamics in site-diluted Josephson-junction arrays.

Measurements of the IV characteristics of site-diluted Josephson-junction arrays have revealed intriguing effects of percolative disorder on the phase transition and the vortex dynamics in a two-dimensional XY system. Different from other types of phase transitions, the Kosterlitz-Thouless transition was eliminated with the introduction of percolative disorder far below the percolation threshold. Even after the Kosterlitz-Thouless order had been removed, the system remained superconducting at low temperatures by establishing a different type of order.

Critical behavior of frustrated Josephson junction arrays with bond disorder.

The scaling behavior of the current-voltage (IV) characteristics of a two-dimensional proximity-coupled Josephson junction array (JJA) with quenched bond disorder was investigated for frustrations f = 1/5, 1/3, 2/5, and 1/2. For all these frustrations including 1/5 and 2/5 where a strongly first-order phase transition is expected in the absence of disorder, the IV characteristics exhibited a good scaling behavior. The critical exponent nu indicates that bond disorder may drive the phase transitions to be continuous but not into the Ising universality class, contrary to what was observed in Monte Carlo simulations.