>TIGR01793 cit_synth_euk citrate (Si)-synthase, eukaryotic; InterPro: IPR010109 Citrate synthase 2.3.3.1 from EC is a member of a small family of enzymes that can directly form a carbon-carbon bond without the presence of metal ion cofactors. It catalyses the first reaction in the Krebs' cycle, namely the conversion of oxaloacetate and acetyl-coenzyme A into citrate and coenzyme A. This reaction is important for energy generation and for carbon assimilation. The reaction proceeds via a non-covalently bound citryl-coenzyme A intermediate in a 2-step process (aldol-Claisen condensation followed by the hydrolysis of citryl-CoA). Citrate synthase enzymes are found in two distinct structural types: type I enzymes (found in eukaryotes, Gram-positive bacteria and archaea) form homodimers and have shorter sequences than type II enzymes, which are found in Gram-negative bacteria and are hexameric in structure. In both types, the monomer is composed of two domains: a large alpha-helical domain consisting of two structural repeats, where the second repeat is interrupted by a small alpha-helical domain. The cleft between these domains forms the active site, where both citrate and acetyl-coenzyme A bind. The enzyme undergoes a conformational change upon binding of the oxaloacetate ligand, whereby the active site cleft closes over in order to form the acetyl-CoA binding site . The energy required for domain closure comes from the interaction of the enzyme with the substrate. Type II enzymes possess an extra N-terminal beta-sheet domain, and some type II enzymes are allosterically inhibited by NADH . This entry includes both mitochondrial and peroxisomal forms of citrate synthase. Peroxisomal forms of the enzyme, recognized by the C-terminal targeting motif SKL, act in the glyoxylate cycle. Eukaryotic homologs include a Tetrahymena thermophila citrate synthase that doubles as a filament protein, a putative citrate synthase from Plasmodium falciparum (no TCA cycle), and a methylcitrate synthase from Aspergillus nidulans (Emericella nidulans).; GO: 0004108 citrate (Si)-synthase activity, 0044262 cellular carbohydrate metabolic process.

Probab=100.00 E-value=0 Score=522.71 Aligned_cols=348 Identities=31% Similarity=0.452 Sum_probs=309.8 Q ss_pred EEEEEEEEEECCCCEEEECCEEHHHHH------HH---CCHHHHHHHHHCCCCCCHHHHHHHHHHHHHCCCCCHHHHHHH Q ss_conf 878756543344777898993199997------50---898999999981879998999999998864068998999999 Q gi|254780355|r 51 SCKSKITFIDGNNGILLYRGYPIEQLS------EK---SDFLEVCYLLLHGELANVSQQKDFNDKISRHALLNENMSRFF 121 (429) Q Consensus 51 ~ceS~IT~IDG~~G~L~YRGY~IedLa------~~---~sFeEVayLLl~GeLPt~~el~~F~~~l~~~~~lpe~v~~~i 121 (429) T Consensus 50 vwEt--SvLDpEEGI-RFRGlsIPECQKLLPkAkgGeEPLPEgl~WLLlTG~VPse~Qv~alsaEw~aRadlP~hv~~~i 126 (430) T TIGR01793 50 VWET--SVLDPEEGI-RFRGLSIPECQKLLPKAKGGEEPLPEGLLWLLLTGEVPSEEQVDALSAEWRARADLPKHVVKLI 126 (430) T ss_pred EEEC--CCCCCCCCE-ECCCCCCCHHHHCCCCCCCCCCCCHHHHHHHHHCCCCCHHHHHHHHHHHHHHHHHHHHHHHHHH T ss_conf 2204--302665460-1278864114410777456579746899999845899808899999999985500278999998 Q ss_pred HHHCCCCCHHHHHHHHHHHHHH---H----HCCCCCCCCHHHHHHHHHHHHHHHHHHHHHHHH--HHCCCCCCCCCCCHH Q ss_conf 8512476525789999999875---2----068557678788988899999999999999999--727985348886424 Q gi|254780355|r 122 MGFPSSAHPMAMLVSAVGALSS---F----YYSPSGVQDLEQCVNVSLRMIAKISTIAAMIYK--YSIGQPFVYPRSDLD 192 (429) Q Consensus 122 ~~~p~~ahPM~~L~~~vsaL~a---~----~~~~~~~~d~~~~~~~a~rLiA~~p~i~A~~yr--~~~G~~~i~Pd~~ls 192 (429) T Consensus 127 D~~P~tlHPMaQF~~av~AL~~eS~FakAyakGi~K~~YWeytyEDS~dLiAkLPtvAA~IYRn~ykdG~~v~~id~~kD 206 (430) T TIGR01793 127 DALPSTLHPMAQFALAVAALEVESEFAKAYAKGIAKKKYWEYTYEDSMDLIAKLPTVAAKIYRNLYKDGKAVASIDDKKD 206 (430) T ss_pred HHCCCCCCHHHHHHHHHHHHHHHHHHHHHHHHCCCCCCCCCCCHHHHHHHHHHHHHHHHHHHHHHHCCCEEEEEECCCCC T ss_conf 50574357278999999988741045336772554112457304447999984369999999866128805773167654 Q ss_pred HHHHHHHHHCCCCCCCCCCCHHHHHHHHHHHHEECCCC-CCCHHHHHHHHHCCCCCHHHHHHHHHHHHHHHHHCCCCHHH Q ss_conf 68877876428984101479699999875635013678-76301555544205654246776755421002220352899 Q gi|254780355|r 193 YASNFLHMCFSVPCAEYQVNPLLARAMNRIFILHADHE-QNASTSTVRLAGSSGADPFACIAAGVACLGGRAHGGANEEA 271 (429) Q Consensus 193 yaeNfL~Ml~~~~~~~~~~~~~~~~ald~~LILhADHe-~NaSTft~R~vaSt~adlysai~agi~aL~GPlHGGAne~v 271 (429) T Consensus 207 ysaNfa~~LGy------aD~p~f~ELMRLYltIHsDHEGGNVSAHT~HLVgSALSdPyLSfaAalnGLAGPLHGLANQEV 280 (430) T TIGR01793 207 YSANFASMLGY------ADDPSFAELMRLYLTIHSDHEGGNVSAHTSHLVGSALSDPYLSFAAALNGLAGPLHGLANQEV 280 (430) T ss_pred CHHHHHHHCCC------CCCHHHHHHHHHHHEEEECCCCCCCCHHHHHHHHHHHCCHHHHHHHHHHHCCCHHHHHHHHHH T ss_conf 01216751575------678758988662300120148886102457888877316568999986311220113688999 Q ss_pred HHHHHHC----C----CCCHHHHHHHHHHHCCCCCEEECCCCCCCCCCCHHHHHHHHHHHHHHHHCCCCCCHHHHHHHHH Q ss_conf 9998621----5----5351279999998214786143027743555540346899999998886087765179999999 Q gi|254780355|r 272 LNMLMEI----G----SLERIPHYIMRAKDKNDPFRIMGFGHRVYRNHDPRCRIMRETMYEVLEVTGRFNDPIAQVAIEL 343 (429) Q Consensus 272 ~~ml~~I----~----~~~~v~~~i~~~~~~~~~~ri~GfGHrvyk~~DPRa~~l~~~~~~l~~~~~~~~~~~~~~a~~l 343 (429) T Consensus 281 L~wl~~~v~e~G~~n~t~eqlKdy~WktLnsG~--VVPGYGHaVLRkTDPRY~cQREFALk~L-----PdDplFkLVS~l 353 (430) T TIGR01793 281 LVWLKEVVKEVGEDNLTEEQLKDYVWKTLNSGK--VVPGYGHAVLRKTDPRYICQREFALKHL-----PDDPLFKLVSQL 353 (430) T ss_pred HHHHHHHHHHHCCCCCCHHHHHHHHHHHHCCCC--EECCCCCCCCCCCCCCCCCHHHHHHHCC-----CCCHHHHHHHHH T ss_conf 999998877517887747678999997605895--4257665202688988431288883317-----896156886410 Q ss_pred HHHH--HHHHHCCCCCCCCCCCHHHHHHHHHCCC-CHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCCCCCCCCCC Q ss_conf 9999--6115314579877844788999998499-9668589999999989999999997078983004562105 Q gi|254780355|r 344 ERIA--LEDEYFIERKLYPNVDFYSGITLRALGF-PTNLFTVLFAVARTAGWVSQWTEMIVDPSRRIGRPRQLYT 415 (429) Q Consensus 344 e~~a--~~d~~~~~r~l~pNvDfysg~i~~~lGi-p~~~ft~iFa~~R~~Gw~AH~~Eq~~~~~~ri~RP~~~Y~ 415 (429) T Consensus 354 yki~PgiLtE~GK~KNPwPNVDaHSGVLLqyyGlTE~~yYTVLFGVSRAlG~lsQLiwdRa~G-lPlERPKS~st 427 (430) T TIGR01793 354 YKIVPGILTELGKVKNPWPNVDAHSGVLLQYYGLTEARYYTVLFGVSRALGVLSQLIWDRALG-LPLERPKSFST 427 (430) T ss_pred HCCCCCCEECCCCCCCCCCCCCCHHHHHHHHCCCCCCCCHHHHHHHHHHHHHHHHHHHHHHCC-CCCCCCCCCCC T ss_conf 101685000478757867787520116764024000021034334668874436899986568-98568866534

HHsearch alignment for GI: 254780355 and conserved domain: TIGR01793