>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=99.13 E-value=1.8e-08 Score=72.92 Aligned_cols=281 Identities=16% Similarity=0.223 Sum_probs=168.5 Q ss_pred CCCCHHHHHHHHHHHHHCCCCCEEEECCCCHHHHHHHHHHCCCCCCCCHHHHCCH-H--HHHH-HHHCCCCCEEECCCCH Q ss_conf 6885899999999840128885167416602456556663168971004542026-7--7526-6640876403056881 Q gi|254780486|r 71 CGNYNQHLELEEEAADFFGFEKMLYFGSGYAANMAILSTLPQATDLIVYDKLVHA-S--IREG-INSGKAQAIAIPHNNI 146 (381) Q Consensus 71 ~G~~~~~~~lE~~lA~~~g~e~al~~~sG~~An~~~i~~l~~~~d~ii~D~~~Ha-S--i~~g-~~ls~a~~~~f~HnD~ 146 (381) T Consensus 48 sGN-PTRd~l~~aLA~LE~G~~AVvT~~GMsAI~L~~~~lL~pdDLlvAPHDCYGGtYRLl~~lA~kG~~~v~fVDQ~D~ 126 (383) T TIGR02080 48 SGN-PTRDILQQALAELEGGAGAVVTNSGMSAIDLVTTALLGPDDLLVAPHDCYGGTYRLLNALAKKGQFKVQFVDQSDE 126 (383) T ss_pred CCC-CCHHHHHHHHHHHHCCCCCEECCCHHHHHHHHHHHEECCCCEEEECCCCCCCHHHHHHHHHHCCCEEEEEEECCHH T ss_conf 989-7565899999998489982566856898876643120789768804326770488886452078338998607628 Q ss_pred HHHHHHHHHHHHCCCCCCCEEEECCC-CCCCCCHHHHHHHHHHHHHCCEEEEECCCCCCCCCCCCCCEEEEEHHCCCCCC Q ss_conf 47899764310002478607971462-15766134689999986313608986131122234777640110000134652 Q gi|254780486|r 147 NSFAENINKWRKSGGKGFPWIVVESI-YSMDGDKAPLDDLVKIANDYDGFIVVDEAHATGVCGPLGKGLTHIIEERNNVI 225 (381) Q Consensus 147 ~~Le~~l~~~~~~~~~~~~~vv~egv-~Sm~G~~apL~~i~~l~~~y~~~LivDEah~~Gv~G~~G~G~~~~~~~~~~~i 225 (381) T Consensus 127 ~al~~ALa~kd------PKLVlIEtPSNPLl-RVVDI~~lc~La~~~G~~vvVDNT----FLsP~---lQ~PL-~LGAD~ 191 (383) T TIGR02080 127 QALEAALAQKD------PKLVLIETPSNPLL-RVVDIAKLCKLAKAVGAVVVVDNT----FLSPI---LQQPL-SLGADL 191 (383) T ss_pred HHHHHHHHHCC------CCEEEEECCCCCCC-HHHHHHHHHHHHHHCCEEEEEECC----CCCHH---HCCCC-CHHCCE T ss_conf 99999997469------84799867998852-188899999887618838998552----16776---72753-011113 Q ss_pred CCCCCCCCC-CC---EEE-EEECCCCCCCCCCCCCCCEECCCCCCCCHHHHHHHHHHHHHHCCCH-HHHHHHHHHHHHHH Q ss_conf 100134656-53---026-7524510010000121100001357750257898878988627102-24789999999987 Q gi|254780486|r 226 VMHSCSKAL-GS---SGA-LVGSNKIIYDYLINYAKPFIYTTSPSPILAVVACEALKLIKRKPAL-HKSLLQLINITDKI 299 (381) Q Consensus 226 v~~TlsKa~-g~---~GG-~i~~~~~ii~~l~~~~~~~ifst~l~P~~~aaa~aal~~l~~~~~~-~~~l~~~~~~~~~~ 299 (381) T Consensus 192 V~HS~TKYlNGHSDVi~GaVIaKd~q~~e~L~WW~N~l-G~-tG~aFDSY~tLRGlRTL~~Rm~~~qrnA~~Iv~yL~~~ 269 (383) T TIGR02080 192 VIHSTTKYLNGHSDVIAGAVIAKDPQLAEELAWWANAL-GV-TGGAFDSYLTLRGLRTLAARMRSQQRNAQTIVEYLQTQ 269 (383) T ss_pred EHHHHHCCCCCCHHHHHHHHHCCCHHHHHHHHHHHHCC-CC-CCCHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHCC T ss_conf 01111100034034312124014712234433343002-55-44434688998678888888888878899999998448 Q ss_pred H-HCCCCCCC----------------CCCEEEEEE-CCHHHHHHHHHHHHHCCEEE---------EEECCCCC------- Q ss_conf 6-41797899----------------897289995-89799999999999779189---------86228888------- Q gi|254780486|r 300 A-NKKIGFSS----------------QSHIQSIVI-GDNKSCLNIAKNLQKKGFDI---------RAIRPPTV------- 345 (381) Q Consensus 300 ~-~~~~g~~~----------------~s~I~~v~~-gd~~~a~~~~~~L~~~Gi~v---------~~i~~PtV------- 345 (381) T Consensus 270 P~V~k~YyPgLpdH~GH~IA~~QQ~GFGAmlSFEL~G~~~~v~~FL~~L---~LFtLAESLGGVESLiaHPATMTH~aM~ 346 (383) T TIGR02080 270 PLVKKVYYPGLPDHPGHEIAARQQKGFGAMLSFELKGGEEAVRRFLGKL---SLFTLAESLGGVESLIAHPATMTHAAMG 346 (383) T ss_pred CCEEEEECCCCCCCCCHHHHHHHCCCCCCEEEEEECCCHHHHHHHHHHC---CCHHHHHHHCCHHHHHCHHHCCCCHHHH T ss_conf 9402633587888667699986256543302333218868999998431---4012123315512333301012602101 Q ss_pred -------CCCCCEEEEECCCCCCHHHHHHHHHHHHHHH Q ss_conf -------8887039996287899999999999999998 Q gi|254780486|r 346 -------PINTARLRISITLNVDEPTIVKLFDILPQII 376 (381) Q Consensus 346 -------p~~~~rlRi~v~a~~t~edi~~~~~~l~~v~ 376 (381) T Consensus 347 ~eAR~~AGI~~~LLRlSvGl----ED~~DLiaDL~~gl 380 (383) T TIGR02080 347 PEARAEAGISDTLLRLSVGL----EDADDLIADLDQGL 380 (383) T ss_pred HHHHHHCCCCCCCCEEEEEE----CCHHHHHHHHHHHH T ss_conf 89897458411420002100----34688999999997

HHsearch alignment for GI: 254780486 and conserved domain: TIGR02080