DNAL1 and escherichia coli infection: Furthermore, it remains controversial which of the three main PGRPLC isoforms (LC1, LC2 or LC3) is the sensor of Lysine-type PGN of Gram-positive bacteria and DAP-type PGN of Gram-negative bacteria and some Gram-positive bacilli, as mosquito survival assays implicated all 3 isoforms to different extents in defense against S. aureus and E. coli infections, with PGRPLC3 exhibiting the strongest RNAi phenotype [23].