Functional analysis of a C-terminally altered TonB protein of Escherichia coli.
Deletions within the 3'-end of the cloned Escherichia coli tonB gene were constructed and recombined into the chromosome. Deletions affecting the last eight C-terminal amino acids (aa) yielded functionally active TonB, whereas deletion of the last 15 C-terminal aa, which removed the C-terminal hydrophobic region of TonB, abolished TonB function entirely. Distribution of TonB within cell compartments was not significantly affected by any of the deletions. All deletion derivatives were less stable than wild-type TonB. A major degradation product of approx. 29 kDa was observed for all TonB derivatives, indicating that it was an N-terminal fragment. The possibility is discussed that the C-terminal hydrophobic region is involved in the intramolecular interaction rather than in the membrane association of TonB.
Fakultät für Biologie, Universität Konstanz, F.R.G.
M
M
Anton
K J
KJ
Heller
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001435:Bacteriophages / Q000378:metabolism; D001483:Base Sequence; D001692:Biological Transport / Q000235:genetics; D003001:Cloning, Molecular; D003087:Colicins / Q000494:pharmacology; D004252:DNA Mutational Analysis; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005291:Ferrichrome / Q000494:pharmacology; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D014169:Transformation, Bacterial / Q000235:genetics; D014805:Vitamin B 12 / Q000494:pharmacology
D001426:Bacterial Proteins; D003087:Colicins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D010446:Peptide Fragments; C057616:tonB protein, Bacteria; C489181:tonB protein, E coli; D005291:Ferrichrome; D014805:Vitamin B 12