Open AccessA DNA binding protein showing sequence specificity for a region containing the replication origin ofXenopus laevismitochondria DNA
Author(s) -
Agnès Cordonnier,
Dominique Du-Bluteau,
Gilbert Brun
Publication year - 1987
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/15.2.477
Subject(s) - biology , xenopus , dna , dna clamp , dna replication , dna binding protein , hmg box , microbiology and biotechnology , biochemistry , dna polymerase ii , mitochondrial dna , rna , gene , reverse transcriptase , transcription factor
In Xenopus laevis mitochondria up to 14 different polypeptides with affinity for the DNA, have been identified by the protein blotting technique. Under stringent binding conditions only one polypeptide displayed specific affinity for a restriction fragment containing the H strand origin of replication of the Xenopus laevis mt chromosome. The proteins were fractionated by double stranded DNA cellulose chromatography. Under conditions which favor high affinity interactions between proteins and DNA, a protein of the 2M NaCl step shows specific binding to the DNA fragments containing the D-loop region. Some physical properties of the protein have been studied. It has a MW of 21.5 Kd and a globular shape as can be inferred from the relationship between MW and sedimentation coefficient (2.7 S). It binds non cooperatively to DNA and forms relatively stable complexes as demonstrated by DNA competition experiments.