Lipoprotein 28, an inner membrane protein of Escherichia coli encoded by nlpA, is not essential for growth.

Lipoprotein 28, an inner membrane protein of Escherichia coli encoded by nlpA, was found to be nonessential for cell growth. A deletion strain in which most of the coding region of the nlpA gene was replaced by a kanamycin resistance gene was able to grow under various conditions. No discernible differences between the wild type and the deletion strain were observed in terms of cell morphology and sensitivity to various chemicals, except for kanamycin.