When the lactose (lac) permease of Escherichia coli is expressed from the lac promoter at relatively low rates, deletion of amino acid residues 2-8 (delta 7) or 2-9 (delta 8) from the hydrophilic N te
1. Serine (S) and threonine (T) were replaced with alanine (A) at S2056 and T2609 cluster sites.2. V3-KC23 mutant carries a frame-shift at position of amino acid 3715 that results in truncation of the
