2.0 2015-09-08 17:50:19 -0600 2015-09-14 16:46:11 -0600 ECMDB24231 M2MDB006348 S-ribosyl-L-homocysteine S-Ribosyl-L-homocysteine is a member of the chemical class known as Alpha Amino Acids and Derivatives. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon). AI-2 is spontaneously derived from 4,5-dihydroxy-2,3-pentanedione that, along with homocysteine, is produced by cleavage of S-adenosylhomocysteine (SAH) and S-ribosylhomocysteine by the Pfs and LuxS enzymes. (PMID 16885435) C9H14NO6S 264.27 264.054183349 (1-carboxylato-3-{[(3,4,5-trihydroxyoxolan-2-yl)methyl]sulfanyl}propyl)azaniumyl (1-carboxylato-3-{[(3,4,5-trihydroxyoxolan-2-yl)methyl]sulfanyl}propyl)ammonio [N+]C(CCSCC1OC(O)C(O)C1O)C([O-])=O InChI=1S/C9H15NO6S/c10-4(8(13)14)1-2-17-3-5-6(11)7(12)9(15)16-5/h4-7,9,11-12,15H,1-3H2,(H,13,14)/q+1/p-1 QUDMRZABJLFLCP-UHFFFAOYSA-M logp -2.10 ALOGPS logs -1.08 ALOGPS solubility 2.69e+01 g/l ALOGPS logp -2.9 ChemAxon pka_strongest_acidic 1.63 ChemAxon pka_strongest_basic -3.7 ChemAxon iupac (1-carboxylato-3-{[(3,4,5-trihydroxyoxolan-2-yl)methyl]sulfanyl}propyl)azaniumyl ChemAxon average_mass 264.27 ChemAxon mono_mass 264.054183349 ChemAxon smiles [N+]C(CCSCC1OC(O)C(O)C1O)C([O-])=O ChemAxon formula C9H14NO6S ChemAxon inchi InChI=1S/C9H15NO6S/c10-4(8(13)14)1-2-17-3-5-6(11)7(12)9(15)16-5/h4-7,9,11-12,15H,1-3H2,(H,13,14)/q+1/p-1 ChemAxon inchikey QUDMRZABJLFLCP-UHFFFAOYSA-M ChemAxon polar_surface_area 133.11 ChemAxon refractivity 68.8 ChemAxon polarizability 25.52 ChemAxon rotatable_bond_count 6 ChemAxon acceptor_count 6 ChemAxon donor_count 3 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::NmrOneD 246288 Specdb::NmrOneD 246289 Specdb::NmrOneD 246290 Specdb::NmrOneD 246291 Specdb::NmrOneD 246292 Specdb::NmrOneD 246293 Specdb::NmrOneD 246294 Specdb::NmrOneD 246295 Specdb::NmrOneD 246296 Specdb::NmrOneD 246297 Specdb::NmrOneD 246298 Specdb::NmrOneD 246299 Specdb::NmrOneD 246300 Specdb::NmrOneD 246301 Specdb::NmrOneD 246302 Specdb::NmrOneD 246303 Specdb::NmrOneD 246304 Specdb::NmrOneD 246305 Specdb::NmrOneD 246306 Specdb::NmrOneD 246307 Specdb::MsMs 1316317 Specdb::MsMs 1316318 Specdb::MsMs 1316319 Specdb::MsMs 1430773 Specdb::MsMs 1430774 Specdb::MsMs 1430775 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase P0AF12 MTNN_ECOLI mtnN http://ecmdb.ca/proteins/P0AF12.xml S-ribosylhomocysteine lyase P45578 LUXS_ECOLI luxS http://ecmdb.ca/proteins/P45578.xml S-Adenosylhomocysteine + Water > Adenine + S-ribosyl-L-homocysteine + S-ribosyl-L-homocysteine PW_R003067 S-ribosyl-L-homocysteine + S-ribosyl-L-homocysteine > Homocysteine + autoinducer 2 + Homocysteine + autoinducer 2 PW_R003068 S-ribosyl-L-homocysteine > 4,5-Dihydroxy-2,3-pentanedione + Homocysteine PW_R005929