Open AccessIdentification, isolation, and characterization of the structural gene encoding the delta' subunit of Escherichia coli DNA polymerase III holoenzyme
Author(s) -
J R Carter,
Mary Ann Franden,
R Aebersold,
Charles S. McHenry
Publication year - 1993
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.175.12.3812-3822.1993
Subject(s) - biology , microbiology and biotechnology , gene , open reading frame , nucleic acid sequence , genetics , polymerase , peptide sequence
The gene encoding the delta' subunit of DNA polymerase III holoenzyme, designated holB, was cloned by a strategy in which peptide sequence was used to derive a DNA hybridization probe. The gene maps to 24.95 centisomes of the chromosome. Sequencing of holB revealed a 1,002-bp open reading frame predicted to produce a 36,936-Da protein. The gene has a ribosome-binding site and promoter that are highly similar to the consensus sequences and is flanked by two potential open reading frames. Protein sequence analysis of delta' revealed a high degree of similarity to the dnaX gene products of Escherichia coli and Bacillus subtilis, including one stretch of 10 identical amino acid residues. A lesser degree of similarity to the gene 44 protein of bacteriophage T4 and the 40-kDa protein of the A1 complex (replication factor C) of HeLa cells was seen. The gene, when placed into a tac promoter-based expression plasmid, directed expression of two proteins of similar size. By immunodetection with anti-holoenzyme immunoglobulin G, both proteins are judged to be products of holB.