>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=99.81 E-value=4.6e-19 Score=130.29 Aligned_cols=139 Identities=19% Similarity=0.350 Sum_probs=96.7 Q ss_pred EEECCCCCCCCHHHHHHHHHHHHHCCCCEEEEEECCCCCCCCCCCCCCHHHHHHHHHHHCC-CCCCCCCHHHHHHHHHHH Q ss_conf 9827789713389999999999862998899997589987555668899999999863104-753213425531000328 Q gi|254780649|r 23 GLFGGNFNPPHHGHIEIAQIAIKKLNLDQLWWIITPFNSVKNYNLSSSLEKRISLSQSLIK-NPRIRITAFEAYLNHTET 101 (216) Q Consensus 23 gifGGSFdPiH~gHl~ia~~~~~~l~ld~v~~ips~~~p~K~~~~~~~~~~R~~m~~~~~~-~~~i~v~~~E~~~~~syT 101 (216) T Consensus 1 AifpGSFDP~t~GHldii~ra~~lF--D~vii~i~-~N~~K~--~~f~~~eR~~~i~~~~~~~~nV~V~~~~-----gl~ 70 (152) T cd02163 1 AVYPGSFDPITNGHLDIIERASRLF--DEVIVAVA-VNPSKK--PLFSLEERVELIREATKHLPNVEVVGFD-----GLL 70 (152) T ss_pred CCCCCCCCCCCCCHHHHHHHHHHHC--CEEEEEEE-CCCCCC--CCCCHHHHHHHHHHHHCCCCCEEEEEEC-----CHH T ss_conf 9078677988400999999999878--98999962-288767--6689999999999974589987999967-----669 Q ss_pred HHHHHHHHCCCCCCCEEEECCCCCHHHHHHHHHHHHHHHHCCEEEEECCCCCHHHHCCHHHHHHHHCCCCHHHHHHHHHC Q ss_conf 99999972013678438961688135777776199999758989993899871432158999986325881233454205 Q gi|254780649|r 102 FHTILQVKKHNKSVNFVWIMGADNIKSFHQWHHWKRIVTTVPIAIIDRFDVTFNYISSPMAKTFEYARLDESLSHILCTT 181 (216) Q Consensus 102 ~dtL~~lk~~~p~~~l~fiiG~D~l~~l~~W~~~~~ll~~~~iiV~~R~g~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 181 (216) T Consensus 71 vd~---ak~~--~a~-~ivRGlR~~~Dfe----yE~~~a~~-----Nr---------------------------~-L~~ 107 (152) T cd02163 71 VDF---ARKV--GAN-VIVRGLRAVSDFE----YEFQMAGM-----NR---------------------------K-LAP 107 (152) T ss_pred HHH---HHHC--CCE-EEEECCCCHHHHH----HHHHHHHH-----HH---------------------------H-HCC T ss_conf 999---9976--982-9996586404889----99999999-----99---------------------------6-089 Q ss_pred CCCEEEEEECCC-CCCCHHHHHHHHHCCCCCCCC Q ss_conf 898099980746-886889999999879685111 Q gi|254780649|r 182 SPPSWLFIHDRH-HIISSTAIRKKIIEQDNTRTL 214 (216) Q Consensus 182 ~~~~~~~i~~~~-~~ISST~IR~~l~~~~~i~~L 214 (216) T Consensus 108 ~IeTvfl~~~~~~~~ISSs~VRel~~~ggdi~~~ 141 (152) T cd02163 108 EIETVFLMASPEYSFISSSLVKEVASLGGDVSGF 141 (152) T ss_pred CCCEEEEECCCCCCEEEHHHHHHHHHCCCCHHHH T ss_conf 9868998479666576189999999839994452

HHsearch alignment for GI: 254780649 and conserved domain: cd02163