Open AccessIsolation and molecular and functional properties of the amino‐terminal domain of colicin A
Author(s) -
KNIBIEHLER Martine,
HOWARD S. Peter,
BATY Daniel,
GELI Vincent,
LLOUBÈS Roland,
SAUVE Paul,
LAZDUNSKI Claude
Publication year - 1989
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1989.tb14700.x
Subject(s) - colicin , amino acid residue , chemistry , amino acid , peptide sequence , amino terminal , domain (mathematical analysis) , biophysics , escherichia coli , biochemistry , biology , gene , mathematical analysis , mathematics
A plasmid was constructed which allowed easy and efficient production and purification of the NH 2 ‐terminal domain of colicin A. In only three steps, an homogenous 18‐kDa polypeptide was obtained. The NH 2 ‐ and COOH‐terminal sequences of the protein were determined and showed that it corresponded to the NH 2 ‐terminal 171 amino acid residues of the 63‐kDa colicin A. Although colicin A is a highly asymmetric protein, hydrodynamic studies indicated that the NH 2 ‐terminal domain (designated AT) has a globular structure. This fragment is not the receptor‐binding domain of colicin A but is required for the transfer of colicin A across the outer membrane of sensitive cells. However, it has a low affinity for phospholipid films and this affinity is not pH‐dependent, in contrast to that of colicin A.