ORGANIZATION OF THE THERMUS-THERMOPHILUS NUSA INFB OPERON AND OVEREXPRESSION OF THE INFB GENE IN ESCHERICHIA-COLI/

The structural gene for translation initiation factor IF2 from Thermus thermophilus was identified on the basis of the N-terminal amino acid sequence of intact T thermophilus IF2 and an internal 25 kDa IF2 frag ment. A total of 5135 bp was cloned and sequenced, comprising the open reading frames for p15A, NusA, p10A, IF2, p10B and SecD, which may fo rm an operon. There are pronounced similarities between the operon arr angement and primary sequence of the T thermophilus genes and proteins , respectively, and their counterparts from other organisms. The T the rmophilus infB gene was expressed to a high level in E coli. Four hund red milligrams of homogenous T thermophilus IF2 were prepared from 60 g of overproducing cells.