Overexpression of gnsA, a multicopy suppressor of the secG null mutation, increases acidic phospholipid contents by inhibiting phosphatidylethanolamine synthesis at low temperatures.

GnsA overproduction was previously found to suppress both the secG null mutation and the fabA6 mutation in Escherichia coli by increasing the unsaturated fatty acid contents. We report here that it also increased the acidic phospholipid contents at 20 degrees C but not at 37 degrees C. GnsA overproduction at 20 degrees C specifically inhibited phosphatidylethanolamine synthesis and therefore caused the increase in the proportion of acidic phospholipids.