Amino acid sequence of the signal peptide of ompA protein, a major outer membrane protein of Escherichia coli.

The structural gene for ompA protein, a major outer membrane protein of Escherichia coli, was cloned using the plasmid cloning vehicle, pMF21. The DNA sequence corresponding to the signal peptide of pro-ompA protein, a secretory precursor of ompA protein, was determined. The amino acid sequence of the signal peptide was deduced from the DNA sequence as follows: Met-Lys-Lys-Thr-Ala-Ile-Ala-Ile-Ala-Val-Ala-Leu-Ala-Gly-Phe-Ala-Thr-Val-Ala-Gin-Ala-. The amino acid sequence complies with all the features of the loop model proposed for the mechanism of protein secretion across the cytoplasmic membrane.