Open AccessTerminase host factor: a histone-likeE.coliprotein which can bind to thecosregion of bacteriophage λ DNA
Author(s) -
Gayle A. Shinder,
Wendy Parris,
Marvin Gold
Publication year - 1988
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/16.7.2765
Subject(s) - biology , dna , deoxyribonuclease i , bacteriophage , microbiology and biotechnology , histone , footprinting , dna binding protein , siphoviridae , escherichia coli , binding site , biochemistry , transcription factor , gene , base sequence
Terminase Host Factor (THF), an E. coli protein capable of fulfilling the host factor requirement for in vitro bacteriophage lambda terminase activity, displays properties characteristic of the prokaryotic type II DNA-binding or "histone-like" proteins. It is a 22 K basic, heat- and acid-stable protein which binds non-specifically to various DNAs. Conditions can be established, however, where THF binds preferentially to the cohesive end site (cos) of lambda DNA forming several distinct complexes as visualized by band retardation in polyacrylamide gels. DNase I footprinting reveals that THF can protect several regions of the top strand on the right side (+) of cos but does not bind as well to the left side (-). The binding regions are separated either by unprotected or by DNase I- hypersensitive bases. Under the conditions used in these experiments, DNA which does not contain cos lambda sequences does not show this pattern of protection. Several repeated motifs in the cos lambda nucleotide sequence may represent a consensus sequence for THF interaction. THF may be similar to other "histone-like" proteins which display both non-specific and selective DNA-binding capacities.