2.0 2015-09-08 17:50:19 -0600 2015-09-14 16:46:41 -0600 ECMDB24232 M2MDB006349 autoinducer 2 Autoinducer 2 (AI-2), a furanosyl borate diester, is a member of a family of signaling molecules used in quorum sensing. AI-2 is unique in that it is one of only a few known biomolecules incorporating boron. First identified in the marine bacterium Vibrio harveyi, AI-2 is produced and recognized by many Gram-negative and Gram-positive bacteria. AI-2 is synthesized by the reaction of 1-deoxy-3-dehydro-D-ribulose with boric acid and is recognized by the two-component sensor kinase LuxPQ in Vibrionaceae (Wikipedia). C5H8O4 132.115 132.042258738 4,5-dihydroxypentane-2,3-dione 4,5-dihydroxy-2,3-pentanedione CC(=O)C(=O)C(O)CO InChI=1S/C5H8O4/c1-3(7)5(9)4(8)2-6/h4,6,8H,2H2,1H3 UYTRITJAZOPLCZ-UHFFFAOYSA-N logp -0.95 ALOGPS logs 0.31 ALOGPS solubility 2.72e+02 g/l ALOGPS logp -0.9 ChemAxon pka_strongest_acidic 11.69 ChemAxon pka_strongest_basic -3 ChemAxon iupac 4,5-dihydroxypentane-2,3-dione ChemAxon average_mass 132.115 ChemAxon mono_mass 132.042258738 ChemAxon smiles CC(=O)C(=O)C(O)CO ChemAxon formula C5H8O4 ChemAxon inchi InChI=1S/C5H8O4/c1-3(7)5(9)4(8)2-6/h4,6,8H,2H2,1H3 ChemAxon inchikey UYTRITJAZOPLCZ-UHFFFAOYSA-N ChemAxon polar_surface_area 74.6 ChemAxon refractivity 29.28 ChemAxon polarizability 12.04 ChemAxon rotatable_bond_count 3 ChemAxon acceptor_count 4 ChemAxon donor_count 2 ChemAxon physiological_charge 0 ChemAxon formal_charge 0 ChemAxon Quorum Sensing Bacterial Autoinducer 2 (AI-2) mediates the quorum sensing 2 system. AI-2 is catalyzed by the luxS enzyme. This enzyme is found in E.coli and S.typhimurium. In E. coli and most pathogenic bacteria that form AI-2 are spontaneous transformations that include cyclization to (2R,4S)-2-methyl-2,4-dihydroxydihydrofuran-3-one and hydration to the final autoinducer (2R,4S)-2-methyl-2,3,3,4-tetrahydroxytetrahydrofuran. This product is released from the cell through the AI-2 transporter (tqsA). As the level of AI-2 increases, other cells detect it and import it through the autoinducer-2 ABC transporter (lsrACDB). AI-2 is then degraded in the cells by phosphorylating the AI-2 which is then isomerized to P-HPD which follows by the transfer of and acetyl group to coenzyme A and releases dihydroxyacetone phosphate PW000836 Signaling S-adenosyl-L-methionine cycle The S-adenosyl-L-methionine cycle starts with S-adenosyl-L-methionine reacting with (a demethylated methyl donor ) dimethylglycine resulting in the release of a hydrogen ion, a betain (a methylated methyl donor) and a S-adenosyl-L-homocysteine. The s-adenosyl-L-homocysteine reacts with a water molecule through a S-adenosylhomocysteine nucleosidase resulting in the release of a adenine and a ribosyl-L-homocysteine. This compound in turn reacts with a s-ribosylhomocysteine lyase resulting in the release of a l-homocysteine and a autoinducer 2. The L-homocysteine reacts with a N5-methyl-tetrahydropteroyl tri-L-glutamate through a methionine synthase resulting in the release of a tetrahydropteroyl tri-L-glutamate and a methione. The methionine in turn reacts with a water molecule and ATP molecule through a methionine adenosyltransferase resulting in the release of a diphosphate, a phosphate and a s-adenosyl-L-methionine. PW002080 Metabolic Specdb::CMs 1085573 Specdb::MsMs 23708 Specdb::MsMs 23709 Specdb::MsMs 23710 Specdb::MsMs 30506 Specdb::MsMs 30507 Specdb::MsMs 30508 S-ribosylhomocysteine lyase P45578 LUXS_ECOLI luxS http://ecmdb.ca/proteins/P45578.xml S-ribosyl-L-homocysteine + S-ribosyl-L-homocysteine > Homocysteine + autoinducer 2 + Homocysteine + autoinducer 2 PW_R003068