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Research has been conducted on the DtxR-dependent iron-regulated promoter from Corynebacterium diphtheriae. The cloning and characterization of this promoter have been carried out via the use of the systematic evolution of ligands by exponential enrichment-like selection method and the details are reported.

A study was conducted to examine the expressions of glnB and a glnB-like gene in a mutant of the nonsulfur purple photosynthetic bacterium Rhodobacter spaeroides. Gamma-glutamyltransferase assay was carried out at pH 7.5 to determine glutamine synthetase levels. Results indicated that glnK expression was derepressed during the presence of ammonia in photoheterotrophic conditions. Findings also showed that carbon metabolism supports a critical function in regulating nitrogen metabolism.

The role of the regB gene in bacterial signal transduction and CO2 fixation regulation in Rhodobacter sphaeroides was studied. Results revealed that aside from photosystem synthesis, the gene also plays a crucial role in the control of the Calvin cycle CO2 fixation operon. When light is available, regulation proceeds anaerobically. In the dark, however, it occurs aerobically. This suggests that regB belongs to a two-component system which codes for a sensor kinase controlling the regulation of light-independent and dependent CO2 fixation and the biosynthesis of the photosystem.