CHAPERONE SECB - CONFORMATIONAL-CHANGES DEMONSTRATED BY CIRCULAR-DICHROISM

The chaperone SecB, which is involved in protein export in Escherichia coli, is shown by circular dichroism measurements to contain a high c ontent of beta-pleated sheets. Prediction of the secondary structure o f SecB is in good agreement with the observed content of beta-sheet. I n accordance with the previous studies in which changes in conformatio n were assessed indirectly [Randall (1992), Science 257, 241-245], her e we show that the conformation of SecB changes with the concentration of salt in the milieu and also when SecB interacts with a peptide lig and.