>TIGR02080 O_succ_thio_ly O-succinylhomoserine (thiol)-lyase; InterPro: IPR011821 Proteins in this entry are important in the interconversion of the sulphur-containing amino acids L-cysteine and L-methionine in bacteria. In bacteria, inorganic sulphur is reduced to sulphide, which is then used to displace the acetyl group of O-acetyl-L-serine to form the essential amino acid L-cysteine. Biosynthesis of L-methionine then occurs via the transsulphuration pathway which involves the sequential action of two pyridoxal 5'-phosphate (PLP) enzymes, cystathionine gamma-synthase (CGS) and cystathionine beta-lyase (CBL). Firstly CGS catalyses the formation of the intermediate cystathione from a homoserine ester and L-cysteine. This intermediate is then converted by CBL to L-homoserine, which is subsequently methylated by methionine synthase to form L-methionine. For more information see . The CGS enzyme (P00935 from SWISSPROT) from Escherichia coli is, like other CGS enzymes, a homotetramer composed of two catalytically active dimers . The active site of each dimer is found at the interface between the monomers and involves residues from each monomer. Catalysis occurs by alpha,gamma-elimination/replacement reactions..

Probab=99.04 E-value=5e-09 Score=74.43 Aligned_cols=291 Identities=21% Similarity=0.237 Sum_probs=167.0 Q ss_pred HHHHHHHHHHHHHHHCCCCHHHEEEECCHHHHHHHHHHHHHHHCCCCCCCCEEEECCCC-CCCCCCCCCCCCC----CCC Q ss_conf 99999999999999729897789886685387644556544210224566458733321-2211122222222----222 Q gi|254781091|r 43 TRLYIEESRRIIADFCGAKPDHVVFTSSATEAANWVLTPHFYQGSHKISIDSLYISAIE-HPAVYAGGHFPSH----KIH 117 (383) Q Consensus 43 ~~~~~e~aR~~ia~~~g~~~~ei~ft~~~T~a~~~~i~~~~~~~~~~~~~~~ii~s~~e-H~s~~~~~~~~~~----~v~ 117 (383) T Consensus 52 TRd~l~~a---LA~LE~G~~--AVvT~~GMsAI~L~~~~lL~p-------dDLlvAPHDCYGGtYRLl~~lA~kG~~~v~ 119 (383) T TIGR02080 52 TRDILQQA---LAELEGGAG--AVVTNSGMSAIDLVTTALLGP-------DDLLVAPHDCYGGTYRLLNALAKKGQFKVQ 119 (383) T ss_pred CHHHHHHH---HHHHHCCCC--CEECCCHHHHHHHHHHHEECC-------CCEEEECCCCCCCHHHHHHHHHHCCCEEEE T ss_conf 56589999---999848998--256685689887664312078-------976880432677048888645207833899 Q ss_pred CCCCCCCCCCCCHHHHHHHHHHHCCCCCCEEEEECCCCCCCCCCCHHHHHHHHCCCCCCCCCCCCCCCCCCCCCCCCCCC Q ss_conf 22222222111023455324431135653265403434443332112356520344653344432336554444433431 Q gi|254781091|r 118 KIPVLSKGIVDIQALTDFLEQRNSTCGIPMIAVMFVNNETGVIQPIKEIAQIVKEYQGILVVDAVQAAGRIPLSIEEIKA 197 (383) Q Consensus 118 ~v~~~~~g~i~~~~l~~~i~~~t~~~~~~LVs~~~~~n~tG~i~pi~~I~~~~~~~g~~~~vD~aqa~g~~~id~~~~~~ 197 (383) T Consensus 120 fV--DQ~---D~~al~~ALa~kd----PKLVlIEtPSNPLlRVVDI~~lc~La~~~G~~vvVDNTFLsP~lQ~PL-~LGA 189 (383) T TIGR02080 120 FV--DQS---DEQALEAALAQKD----PKLVLIETPSNPLLRVVDIAKLCKLAKAVGAVVVVDNTFLSPILQQPL-SLGA 189 (383) T ss_pred EE--ECC---HHHHHHHHHHHCC----CCEEEEECCCCCCCHHHHHHHHHHHHHHCCEEEEEECCCCCHHHCCCC-CHHC T ss_conf 86--076---2899999997469----847998679988521888999998876188389985521677672753-0111 Q ss_pred EEEEECCCC-CCCCCC--CHHHHCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCHHHHHHCCC--CHHHHHHHHH--- Q ss_conf 068730543-322343--20110145742012212247742122222221122210012211001--0024565321--- Q gi|254781091|r 198 DFLIISSHK-LGAPVG--AGALVFREDILLPSPLLRGGDQEKGQRAGTENYAVIGGFAVAAQQMV--KDIQKRSSRV--- 269 (383) Q Consensus 198 D~~~~S~hK-~~GP~G--~G~L~~r~~~~~~~p~~~Gg~~e~~~~~GT~~~~~i~~~~~al~~~~--~~~~~~~~~~--- 269 (383) T Consensus 190 D~V~HS~TKYlNG-HSDVi~GaVIaKd~q~~e~L~--------WW---~N~lG~tG--~aFDSY~tLRGlRTL~~Rm~~~ 255 (383) T TIGR02080 190 DLVIHSTTKYLNG-HSDVIAGAVIAKDPQLAEELA--------WW---ANALGVTG--GAFDSYLTLRGLRTLAARMRSQ 255 (383) T ss_pred CEEHHHHHCCCCC-CHHHHHHHHHCCCHHHHHHHH--------HH---HHCCCCCC--CHHHHHHHHHHHHHHHHHHHHH T ss_conf 1301111100034-034312124014712234433--------34---30025544--4346889986788888888888 Q ss_pred HHHHHHHHHHHHHHHHCCC-CCCC-CCCCC------------CCEEEEEECCCCHHHHHHHHHHCCCEE---EEC---HH Q ss_conf 0123333444443210001-2232-21103------------652289857999999999987589699---871---13 Q gi|254781091|r 270 FAIRDYLEQELKKLIPNII-IYGK-DAERI------------SNTCCFSIPFLKAEVLQIALDLEGIAV---SAG---SA 329 (383) Q Consensus 270 ~~L~~~l~~~l~~~~~~~~-i~~~-~~~~~------------~~i~~~~~~~~~~~~v~~~l~~~gI~v---~~G---~~ 329 (383) T Consensus 256 qrnA~~Iv~yL~~-~P~V~k~YyPgLpdH~GH~IA~~QQ~GFGAmlSFEL~G~~-~~v~~FL~~L~LFtLAESLGGVESL 333 (383) T TIGR02080 256 QRNAQTIVEYLQT-QPLVKKVYYPGLPDHPGHEIAARQQKGFGAMLSFELKGGE-EAVRRFLGKLSLFTLAESLGGVESL 333 (383) T ss_pred HHHHHHHHHHHHC-CCCEEEEECCCCCCCCCHHHHHHHCCCCCCEEEEEECCCH-HHHHHHHHHCCCHHHHHHHCCHHHH T ss_conf 7889999999844-8940263358788866769998625654330233321886-8999998431401212331551233 Q ss_pred HC-CCCCCCCHHHHHCCCCC------CCCEEEEEECCCCCHHHHHHHHHHHHHHHHH Q ss_conf 38-86433101467628887------4765999907888999999999999999986 Q gi|254781091|r 330 CS-SGKIKKNHVLAAMGFDT------SQGAVRVSCGDSTTQEDIDIFLNALQKIIRT 379 (383) Q Consensus 330 C~-~~~~~~~~vl~~~g~~~------~~g~vRiS~~~~nT~~dId~l~~~L~~iv~~ 379 (383) T Consensus 334 iaHPATM----TH~aM~~eAR~~AGI~~~LLRlSvGl----ED~~DLiaDL~~gl~a 382 (383) T TIGR02080 334 IAHPATM----THAAMGPEARAEAGISDTLLRLSVGL----EDADDLIADLDQGLQA 382 (383) T ss_pred HCHHHCC----CCHHHHHHHHHHCCCCCCCCEEEEEE----CCHHHHHHHHHHHHHC T ss_conf 3301012----60210189897458411420002100----3468899999999741

HHsearch alignment for GI: 254781091 and conserved domain: TIGR02080