Table 1

Role of T2S and individual T2S substrates in intracellular infection

Strain 130b proteinStrain 130b ORFProtein activity or sequence noveltyRole in intracellular infection of:aReference(s) or sourceb
U937A. castellaniiH. vermiformisN. lovaniensis
LspFclpw13701T2S apparatus++++++++++16, 19, 22
LapAlpw30701Leu/Tyr aminopeptidase19
LapBlpw00321Lys/Arg aminopeptidase19
LegPlpw32851Eukaryotic-likeThis study
LipAlpw08251Monoacylglyercol lipase57
LipBlpw12111Triacylglycerol lipase57
Maplpw11671Acid phosphatase33
NttAlpw13951Novel at this time++This study
NttBlpw28721Novel at this timeThis study
PlaAlpw25361Lysophospholipase A51
PlcAlpw05821Phospholipase C57
PlcBlpw14741Phospholipase Ce7
ProAlpw05471Metalloprotease+++18, 20
SrnAlpw31111T2 RNase++34
  • a Based upon comparing the infectivity of parental strain 130b to a mutant lacking the indicated protein. −, no difference; +, mutant impaired 2- to 10-fold; ++, mutant impaired 11- to 100-fold; +++, mutant impaired >100-fold. U937, U937 cell macrophages.

  • b Where appropriate, relevant previous studies are cited.

  • c Similar results were obtained when mutants lacking LspD, LspE, or LspG were examined (15).

  • d GCAT, glycerophospholipid:cholesterol acyltransferase.

  • e Putative, based upon very high similarity to PlcA.