Open AccessIdentification of DNA restriction fragments of corynebacteriophage β corresponding to hypotoxic peptides of diphtheria toxin
Author(s) -
Bjorn Michael J.,
Kaplan Donald A.,
Collier R.John
Publication year - 1983
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1983.tb00112.x
Subject(s) - ecori , diphtheria toxin , toxin , microbiology and biotechnology , restriction site , biology , restriction fragment , dna , escherichia coli , recombinant dna , restriction map , corynebacterium diphtheriae , restriction enzyme , plasmid , genetics , gene , diphtheria , virology , vaccination
An Xba I/ Eco RI restriction fragment (ca. 2000 bp) from corynebacteriophage β DNA was shown to contain the entire structural gene ( tox ) for diphtheria toxin, plus about 500 bp upstream from the amino terminus of the mature toxin. Restriction analysis and partial sequencing of this fragment permitted us to identify 3 large subfragments coding for hypotoxic peptides of diphtheria toxin. Two Mbo I restriction fragments, F1 (ca. 825 bp) and F3 (ca. 1000 bp), contained regions coding for the enzymatically active A fragment and most of the B fragment, respectively, of the toxin. An Msp I fragment, F2 (ca. 1450 bp), encoded a toxin peptide corresponding approximately to CRM45, a chain termination fragment lacking the carboxyl terminal region of the toxin. Fragments F1, F2, and F3 are permissible to clone in Escherichia coli under P1 + EK1 conditions according to current recombinant DNA guidelines.