Sequences of the malE gene and of its product, the maltose-binding protein of Escherichia coli K12.

The sequences of the malE gene and of its mature product, the maltose-binding protein, have been determined and are in good agreement. The malE gene encodes the pre-protein (396 amino acid residues) which yields, upon cleavage of the NH2-terminal extension (26 amino acid residues), the mature maltose-binding protein (370 amino acid residues). The malE mRNA could form stable stem and loop structures, some of which may account for translational pauses observed by Randall et al. (Randall, L., Josefsson, L. G. & Hardy, S. J. S. (1980) Eur. J. Biochem. 107, 375-379). The sequence change due to an in-frame nonpolar deletion of 765 nucleotides in malE is also presented as well as homologies between the maltose-binding protein and other sugar-binding proteins.