EC Number   |
General Information |
Reference |
|---|
   2.3.1.269 | evolution |
apolipoprotein N-acyltransferase (Lnt) belongs to the nitrilase superfamily. Nitrilases are multimeric proteins that contain a common Glu-Lys-Cys catalytic triad that hydrolyse carbon-nitrogen bonds |
758353 |
| 2.3.1.269 | evolution |
apolipoprotein N-acyltransferase Lnt is Lnt is a reverse amidase and belongs to the nitrilase superfamily. Nitrilases generally require the Glu/Lys/Cys catalytic triad's conformation, also found in Lnt, and have a conserved alphabetabetaalpha sandwich fold. First, the intermediate is formed by the nucleophilic attack on the sn-1-glycerophospholipid's carbonyl (in phosphatidylethanolamine (PE), preferentially). Second, the intermediate (acyl-Lnt) undergoes a nucleophilic attack by the alpha-amino group of the protein substrate generating the triacylated lipoprotein |
756949 |
| 2.3.1.269 | evolution |
the enzyme is a member of the nitrilase superfamily which catalyses hydrolysis or condensation of carbon-nitrogen amine and nitrile bonds |
757766 |
| 2.3.1.269 | malfunction |
Acinetobacter species can tolerate a complete loss-of-function mutation in gene lnt. Absence of a fully functional Lnt impairs modification of lipoproteins, increases outer membrane permeability and susceptibility to antibiotics, and alters normal cellular morphology. In addition, loss of lnt triggers a global transcriptional response to this added cellular stress. Without Lnt, the bacterial cell envelope becomes more permeable and modification of outer membrane lipoproteins is impaired. Cells of the lnt mutant have structural defects. The genome expression profile of Acinetobacter baylyi changes in response to lnt mutation. Phenotypes, overview |
-, 757623 |
| 2.3.1.269 | malfunction |
Acinetobacter species can tolerate a complete loss-of-function mutation in gene lnt. Absence of a fully functional Lnt impairs modification of lipoproteins, increases outer membrane permeability and susceptibility to antibiotics, and alters normal cellular morphology. In addition, loss of lnt triggers a global transcriptional response to this added cellular stress. Without Lnt, the bacterial cell envelope becomes more permeable and modification of outer membrane lipoproteins is impaired. Phenotypes, overview |
-, 757623 |
| 2.3.1.269 | malfunction |
depletion of apolipoprotein N-acyltransferase causes mislocalization of outer membrane lipoproteins in Escherichia coli |
748159 |
| 2.3.1.269 | metabolism |
genome expression profile of Acinetobacter baylyi changes in response to gene lnt mutation, overview |
-, 757623 |
| 2.3.1.269 | metabolism |
in Gram-negative bacteria, lipid modification of proteins is catalysed in a three-step pathway. Apolipoprotein N-acyl transferase (Lnt) catalyses the third step in this pathway, whereby it transfers an acyl chain from a phospholipid to the amine group of the N-terminal cysteine residue of the apolipoprotein |
757766 |
| 2.3.1.269 | metabolism |
three membrane proteins are involved in processing precursors of lipoproteins, in the following order: the diacylglyceryl transferase Lgt, the signal peptidase LspA, and the N-acyltransferase Lnt |
756949 |
| 2.3.1.269 | more |
catalytic mechanism two-step reaction catalysed by Lnt, catalytic residue Cys387, the transacylation reaction uses a ping-pong mechanism, structure of the active site with catalytic triad and Glu343, overview. Lnt activity depends on its affinity to the lipid substrate. The enzyme contains an exo-membrane nitrilase domain fused to a transmembrane (TM) domain. The TM domain of Lnt contains eight TM helices which form a membrane-embedded cavity with a lateral opening and a periplasmic exit. The nitrilase domain is located on the periplasmic side of the membrane, with its catalytic cavity connected to the periplasmic exit of the TM domain. An amphipathic lid loop from the nitrilase domain interacts with the periplasmic lipid leaflet, forming an interfacial entrance from the lipid bilayer to the catalytic centre for both the lipid donor and acceptor substrates. Essential Lnt residues are located within the central cavity. Molecular dynamics simulations |
757766 |
