Abstract
In 2002, the entire genome sequence of thermophilic cyanobacterium Thermosynechococcus elongatus BP-1 was determined. This strain has become a new model organism for genetic engineering and biochemical studies of photosynthesis, because this strain is transformable and protein complexes such as PSII are stable enough for their isolation and crystallization. In this study, we report an improved procedure of transformation that includes antibiotic screening with top agar. Further, we found that T. elongatus BP-1 was naturally transformable with exogenous DNA, and the efficiency was relatively high through a log phase. Based on genome analysis data, tll2230, was presumed to encode type I restriction endonuclease. Disruption of tll2230 enhanced slightly the transformation. We also observed a single-crossover recombination at high frequency in electroporation but hardly any of it in natural transformation.
