Isolation and molecular and functional properties of the amino-terminal domain of colicin A.
A plasmid was constructed which allowed easy and efficient production and purification of the NH2-terminal domain of colicin A. In only three steps, an homogenous 18-kDa polypeptide was obtained. The NH2- and COOH-terminal sequences of the protein were determined and showed that it corresponded to the NH2-terminal 171 amino acid residues of the 63-kDa colicin A. Although colicin A is a highly asymmetric protein, hydrodynamic studies indicated that the NH2-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.
Knibiehler
M
M
Centre de Biochimie et de Biologie Moléculaire du Centre National de la Recherche Scientifique, Marseille, France.
Howard
S P
SP
Baty
D
D
Geli
V
V
Lloubès
R
R
Sauve
P
P
Lazdunski
C
C
D000595:Amino Acid Sequence; D001483:Base Sequence; D003087:Colicins / Q000235:genetics / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D008081:Liposomes; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification*; D010957:Plasmids; D011312:Pressure; D013499:Surface Properties
D003087:Colicins; D008081:Liposomes; D010446:Peptide Fragments