>cd02163 PPAT_a Phosphopantetheine adenylyltransferase (PPAT) is an essential enzyme in bacteria that catalyses a rate-limiting step in coenzyme A (CoA) biosynthesis, by transferring an adenylyl group from ATP to 4'-phosphopantetheine, yielding dephospho-CoA (dPCoA). Each phosphopantetheine adenylyltransferase (PPAT) subunit displays a dinucleotide-binding fold that is structurally similar to that in class I aminoacyl-tRNA synthetases. Superposition of bound adenylyl moieties from dPCoA in PPAT and ATP in aminoacyl-tRNA synthetases suggests nucleophilic attack by the 4'-phosphopantetheine on the -phosphate of ATP. The proposed catalytic mechanism implicates transition state stabilization by PPAT without involving functional groups of the enzyme in a chemical sense in the reaction. The homologous active site attachment of ATP and the structural distribution of predicted sequence-binding motifs in PPAT classify the enzyme as belonging to the nucleotidyltransferase superfamily.

Probab=100.00 E-value=1.1e-35 Score=232.81 Aligned_cols=152 Identities=44% Similarity=0.802 Sum_probs=142.0 Q ss_pred EEECCCCCCCCHHHHHHHHHHHHHCCEEEEECCCCCCCCCCCCCHHHHHHHHHHHHHHHCCCCCCCCEEECCCCCCCCCC Q ss_conf 99658998784899999999997489799964558887665789899999999976420133554412420333332210 Q gi|254780181|r 5 AVYTGSFDPITNGHMDIIIQALSFVEDLVIAIGCNSVKTKGFLSIQERSELIKQSIFHFIPDSSNRVSVISFEGLAVNLA 84 (182) Q Consensus 5 gifgGsFdPiH~GHL~ia~~a~~~~D~vii~~~~~p~k~~~~~s~e~r~~m~~~a~~~~~~~~~~~~~~~~~~~~~~~~~ 84 (182) T Consensus 1 AifpGSFDP~t~GHldii~ra~~lFD~vii~i~~N~~K-~~~f~~~eR~~~i~~~~~~~-----~nV~V~~~~gl~vd~a 74 (152) T cd02163 1 AVYPGSFDPITNGHLDIIERASRLFDEVIVAVAVNPSK-KPLFSLEERVELIREATKHL-----PNVEVVGFDGLLVDFA 74 (152) T ss_pred CCCCCCCCCCCCCHHHHHHHHHHHCCEEEEEEECCCCC-CCCCCHHHHHHHHHHHHCCC-----CCEEEEEECCHHHHHH T ss_conf 90786779884009999999998789899996228876-76689999999999974589-----9879999676699999 Q ss_pred CCCCCEEEEEECCCCCCHHHHHHHHHHHHHHCCCCCEEEEECCCCCCCCCHHHHHHHHHCCCCHHHCCCHHHHHHHHH Q ss_conf 014970799943765201246779989876479986899706857211326999999985999558399999999999 Q gi|254780181|r 85 KDISAQVIVRGLRDMTDFDYEMRMTSVNRCLCPEIATIALFAKESSRYVTSTLIRHLISIDADITSFVPDPVCVFLKN 162 (182) Q Consensus 85 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~l~~~~~~i~l~~~~~~~~ISST~IR~~i~~g~~i~~lVP~~V~~yIk~ 162 (182) T Consensus 75 k~~~a~~ivRGlR~~~DfeyE~~~a~~Nr~L~~~IeTvfl~~~~~~~~ISSs~VRel~~~ggdi~~~VP~~V~~~lk~ 152 (152) T cd02163 75 RKVGANVIVRGLRAVSDFEYEFQMAGMNRKLAPEIETVFLMASPEYSFISSSLVKEVASLGGDVSGFVPPAVAKALKE 152 (152) T ss_pred HHCCCEEEEECCCCHHHHHHHHHHHHHHHHHCCCCCEEEEECCCCCCEEEHHHHHHHHHCCCCHHHHCCHHHHHHHHC T ss_conf 976982999658640488999999999996089986899847966657618999999983999445269999999709

HHsearch alignment for GI: 254780181 and conserved domain: cd02163