단백질의 Folding 을 늦추는 아미노산 잔기의 치환이 단백질 분비에 미치는 영향 = Effect of Amino Acid Substitutions on Protein Translocation at the residues that Slow the Folding of the ribose - binding Protein

다국어 초록 (Multilingual Abstract)

A mutational change in the signal sequence of ribose-binding protein (RBI of E. coli blocks the export of this protein to the periplasm. Intrngenic suppressors for the mutation that have single amino acid substitution in the mature portion of RBP at Ala-27 (A27T) and Val-50 have been characterized previously. In order to assess the role of these amino acids in protein folding and translocation, site-specific mutagenesis approach was employed to substitute various amino acids in those positions. Eight amino acid changes for the position 27, and 11 for the position 50 were obtained. Chemotactic assay showed that 5 out of 8 changes at 27 and 11 of 11 changes at 50 restored taxis to ribose. Pulse-labelling and chase experiment demonstrated that, among RBPs with the suppressor mutation, less stable proteins tend to be more efficiently exported to the periplasm.