Structure of a methionine-rich segment of Escherichia coli Ffh protein.
The methionine-rich segments of the Ffh protein of Escherichia coli and its eukaryotic counterpart SRP54 are thought to bind signal sequences of secretory proteins. The structure of a chemically synthesized 25-residue-long peptide corresponding to one of the proposed methionine-rich amphiphilic helices of Ffh was determined in water and in aqueous trifluroethanol (TFE) solution using CD and NMR. An appreciable alpha-helix conformation exists even in water and this peptide assumes a stable alpha-helix along most of its length in aqueous TFE solution. It is clear that this segment of Ffh protein has a very strong propensity to form alpha-helical structure.
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Taejon, South Korea.
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D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D002942:Circular Dichroism; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D009682:Magnetic Resonance Spectroscopy; D008715:Methionine; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation; D018271:Signal Recognition Particle / Q000737:chemistry*
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C082931:Ffh protein, E coli; D010446:Peptide Fragments; D018271:Signal Recognition Particle; D008715:Methionine