PHYSICAL MAP OF THE LINEAR CHROMOSOME OF STREPTOMYCES-GRISEUS

The chromosomal DNA of Streptomyces griseus 2247 (a derivative of stra in IFO3237) was digested with several restriction endonucleases and an alyzed by pulsed-field gel electrophoresis (PFGE), Digestion with AseI and DraI gave 15 and 9 fragments, respectively, the total sizes of wh ich were 7.8 Mb. All the AseI and DraI fragments were aligned on a lin ear chromosome map by using linking plasmids and cosmids, PFGE analysi s of the intact chromosome also showed a linear DNA band of about 8 Mb , Detailed physical maps of both terminal regions were constructed; th ey revealed the presence of a 24-kb terminal inverted repeat on each e nd. PFGE analysis with and without proteinase K treatment suggested th at each end of the chromosome carries a protein molecule.