ISOLATION, SEQUENCING AND OVEREXPRESSION OF THE GENE ENCODING THE THETA-SUBUNIT OF DNA POLYMERASE-III HOLOENZYME

The gene encoding the theta subunit of DNA polymerase III holoenzyme, designated holE, was isolated using a strategy in which peptide sequen ce was used to derive a DNA hybridization probe. Sequencing of the gen e, which maps to 41.43 centisomes of the chromosome, revealed a 76-cod on open reading frame predicted to produce a protein of 8,846 Da. When placed in a tac promoter expression vector, the open reading frame di rected expression of a protein, that comigrated with authentic theta s ubunit from purified holoenzyme, to 6% of total soluble protein.