Mapping of 61 genes on the refined physical map of the chromosome of Thermus thermophilus HB27 and comparison of genome organization with that of T-thermophilus HB8

We have constructed refined physical maps of the chromosome (1.82 Mb) and the large plasmid pTT27 (250 kb) of Thermus thermophilus HB27. A total of 49 cleavage sites with five restriction enzymes, EcoRI, SspI, Munl, EcoRV and Clal, were determined on the maps. The location of 61 genes was determined by using as probes 64 genes cloned from T. thermophilus or other Thermus strains. Comparison of the genomic organization of the chromosomes of T. thermophilus HB27 and HB8 revealed that they were basically identical, but some genes were located in different regions. Among 32 genes whose locations were determined on both the HB27 and the HB8 chromosomes, the copy number of rpsL-rpsG-fus-tufA, the locations of glyS, pol, and one copy of nusC-rplK-rp/A were different. The 151000 sequence was located only in one region on the HB27 chromosome. In contrast, 151000 sequences were scattered over four regions on the chromosome of HB8. As each region in which glyS, pol, or one copy of nusG-rplK-rplA are present also contained 151000 in HB8, it is suggested that 151000 may play an important role in genomic rearrangements in Thermus strains.