HHsearch alignment for GI: 254780870 and conserved domain: TIGR00418

>TIGR00418 thrS threonyl-tRNA synthetase; InterPro: IPR002320 The aminoacyl-tRNA synthetases (6.1.1. from EC) catalyse the attachment of an amino acid to its cognate transfer RNA molecule in a highly specific two-step reaction. These proteins differ widely in size and oligomeric state, and have limited sequence homology . The 20 aminoacyl-tRNA synthetases are divided into two classes, I and II. Class I aminoacyl-tRNA synthetases contain a characteristic Rossman fold catalytic domain and are mostly monomeric . Class II aminoacyl-tRNA synthetases share an anti-parallel beta-sheet fold flanked by alpha-helices , and are mostly dimeric or multimeric, containing at least three conserved regions , , . However, tRNA binding involves an alpha-helical structure that is conserved between class I and class II synthetases. In reactions catalysed by the class I aminoacyl-tRNA synthetases, the aminoacyl group is coupled to the 2'-hydroxyl of the tRNA, while, in class II reactions, the 3'-hydroxyl site is preferred. The synthetases specific for arginine, cysteine, glutamic acid, glutamine, isoleucine, leucine, methionine, tyrosine, tryptophan and valine belong to class I synthetases; these synthetases are further divided into three subclasses, a, b and c, according to sequence homology. The synthetases specific for alanine, asparagine, aspartic acid, glycine, histidine, lysine, phenylalanine, proline, serine, and threonine belong to class-II synthetases . Threonyl-tRNA synthetase (6.1.1.3 from EC) exists as a monomer and belongs to class IIa. The enzyme from Escherichia coli represses the translation of its own mRNA. The crystal structure of the complex between tRNA(Thr) and ThrRS show structural features that reveal novel strategies for providing specificity in tRNA selection. These include an amino-terminal domain containing a novel protein fold that makes minor groove contacts with the tRNA acceptor stem. The enzyme induces a large deformation of the anticodon loop, resulting in an interaction between two adjacent anticodon bases, which accounts for their prominent role in tRNA identity and translational regulation. A zinc ion found in the active site is implicated in amino acid recognition/discrimination . The zinc ion may act to ensure that only amino acids that possess a hydroxyl group attached to the beta-position are activated .; GO: 0004829 threonine-tRNA ligase activity, 0005524 ATP binding, 0006412 translation, 0006435 threonyl-tRNA aminoacylation, 0005737 cytoplasm.
Probab=100.00  E-value=0  Score=742.09  Aligned_cols=407  Identities=21%  Similarity=0.344  Sum_probs=375.2

Q ss_pred             HHHHHHC-CCC--CCCCCCHHHHHHHCCCEECCCCCHHCCCCHHHHHHHHHHHHHHHHHHCCCEEEECCCCCCHHHHHHC
Q ss_conf             8887310-711--1412561221353032000388111043169999999999999998669889735751246898771
Q gi|254780870|r    7 FLPILQE-NPR--DAEIASHKLMLRTGMIHQHSKGIYSWLPLGQKALDNVNAIIREEQNRTGAIEMSVPTLQSADLWVES   83 (449)
Q Consensus         7 ~~~~l~~-~~~--d~~~~~~~ll~~~g~i~~~~~G~~~~lP~G~~i~~~le~~~r~~~~~~G~~ei~tP~l~~~eL~~~S   83 (449)
T Consensus       170 yl~~~eEa~~r~PDHRklGKeL~Lf~-f~~~~gpG~~~WlPkG~~ir~~ledf~~~~~~~~Gy~~V~TP~m~~~~l~~~s  248 (595)
T TIGR00418       170 YLKRLEEAKKREPDHRKLGKELELFS-FEPEIGPGLPFWLPKGALIRNLLEDFVREKQIKRGYEEVETPIMYDSELWEIS  248 (595)
T ss_pred             HHHHHHHHHCCCCCHHHHHHHHCCCC-CCCCCCCCCEEECCCHHHHHHHHHHHHHHHHHHCCCCCCCCCEECCCCCHHHH
T ss_conf             99999997426857256754531234-58320487414657646789999999999998758864157412156542453


Q ss_pred             CCCHHHHHHHCCHHHCCCCCCEECCCCCCCCCCCHHHCCCCCCCCCEEEEECC-CCCCCCCCCCC-CCCCCEEEEEEECC
Q ss_conf             97311222210402137862000345554310110000134201340264146-53345667675-43453166874042
Q gi|254780870|r   84 GRYDSYGKEMLRLADRNDKAMIYGPTHEEVMTDIFRSHIKSYRNLPFTFYQIQ-LKFRDELRPRF-GVMRSREFLMKDAY  161 (449)
Q Consensus        84 Gh~d~~~~em~~~~d~~~~~~~LrP~~~e~~~~i~~~~~~SYr~LPlr~y~ig-~~fR~E~rp~~-GL~R~ReF~q~D~~  161 (449)
T Consensus       249 GH~~~Y~e~Mf~~~~~~~~~~~LkPMnCpgH~~i~k~~~~SYR~LP~R~aE~g~~~hR~E~sG~L~GL~RvR~FT~dDaH  328 (595)
T TIGR00418       249 GHWDHYKERMFPFTEEDNQEFMLKPMNCPGHILIFKSSLRSYRDLPLRIAELGTTVHRYEKSGALHGLKRVRGFTQDDAH  328 (595)
T ss_pred             HHHHHCCCCCCCCEEECCCCCCCCCCCCHHHHHHHCCCCCCHHHCCCHHHHCCCEEEEEECCCCCCHHHHHHHCCCCCCC
T ss_conf             05450342354010103530334567754453300177777323350343318604788425421010164430699852


Q ss_pred             EECCCHHHHHHHHHHHHHHHHHHHHHCCCHHHHHHHCCHHCCCCHHHHHHHHCCCCCC-EEEECCCCCCCCCCHHHCCHH
Q ss_conf             2118868879999999998741111006201223311001013113343454686770-143101003477641112201
Q gi|254780870|r  162 SFDLTPEGSKHSYNKMFVSYLRIFHRLGLKSIPMRAESGPIGGDLSHEFIVLADTGET-QVFCSKDFMDFPIPSENTDFD  240 (449)
Q Consensus       162 ~F~~~~e~~~~e~~~~~~~~~~i~~~lgl~~~~v~~~~~~ig~~~s~e~~~~~~~~e~-~~~~~~~~~~~~~~~~~~~~~  240 (449)
T Consensus       329 ifc~d~dQi~~E~~~~~~l~~~v~~~fgf~~~~~~LS~R~P--------------e~~~Ky~g~d~~W~~~~~~l~~~l~  394 (595)
T TIGR00418       329 IFCTDEDQIKSEIKNQFRLIQKVYSKFGFSNYKYELSTRDP--------------ENDKKYIGEDELWEKAESALEEALK  394 (595)
T ss_pred             EEECCHHHHHHHHHHHHHHHHHHHHHHCCCCCEEEEEECCC--------------CCCCCCCCCHHHHHHHHHHHHHHHH
T ss_conf             45378677999999999999999887288421689987177--------------7545545887899999999999985


Q ss_pred             HHHCCCCCCCCCCCCCCCCHHHCHHHHHCCCCCCCEEEEEEEECCCEEECCCCCCCCCEEEEECCC--CCC-CCCCCCCC
Q ss_conf             210011220001363212011000233035876552432111158144223112230115896477--772-32336663
Q gi|254780870|r  241 DIISLNSIVEQWTAPYAATSDVHNEKLFDSLPENKRVSARGIEVGHIFYFGTKYSLPMSATFKGAD--GKD-HYVQMGSY  317 (449)
Q Consensus       241 ~~~~~~~~~~~~~~~~~~~~d~~~~~~~d~l~~~~~~~~~~ie~~~~f~lG~~ys~~~~~~~~~~~--g~~-~~~~~g~~  317 (449)
T Consensus       395 ~~~~~yei~~G~~AFYGPKiDf---~~~DaL~R~~q~~TvQlD----f~lPeRF----~l~Y~~~dqd~~~~~Pv~IHra  463 (595)
T TIGR00418       395 ELGVDYEIDEGEGAFYGPKIDF---QIKDALGREWQCATVQLD----FELPERF----DLTYINEDQDNKEKRPVMIHRA  463 (595)
T ss_pred             CCCCCEEEECCCCEEECCEEEE---EEEECCCCHHHCCCEEEE----CCCCCCC----CCEEEEECCCCCCCCCEEEECC
T ss_conf             0798405507881130222688---875101764258814887----1588720----3148420367870067789804


Q ss_pred             CCCCCCCHHHHHHCCCCCCC----CCCCHHHCCCCCEEEECCCCHHHHHHHHHHHHHHHHHCCCEEEEECCCCCHHHHHH
Q ss_conf             44743002332210232111----11363320321102421788799999999999999986987999758979708678
Q gi|254780870|r  318 GIGAMRVVAAVIESSHDGKG----IIWPDSVAPFKISLINIKAHDQVCRDACEKIYARLSKVGCDVFWDDMGEQIGSQFA  393 (449)
Q Consensus       318 giG~~R~~~alle~~~d~~g----~~wP~~iaP~~v~Iipi~~~~~~~~~~A~~i~~~Lr~~Gi~v~~D~r~~~iGkK~~  393 (449)
T Consensus       464 ~~GS~ERfi~iL~E~~~G~fde~~PMLP~WLaP~QV~viPV~i--~~h~~yA~kv~~~L~~~giRv~~D~r~e~lgkKIR  541 (595)
T TIGR00418       464 ILGSIERFIAILLEKYAGAFDERLPMLPLWLAPVQVVVIPVSI--EKHLDYAKKVAEKLKKEGIRVDVDDRNERLGKKIR  541 (595)
T ss_pred             CCHHHHHHHHHHHHHHHHHHHCCCCCCCEECCCEEEEEEECCH--HHHHHHHHHHHHHHHHCCCEEEECCCCCCHHHHHH
T ss_conf             4005899999999875222114689885421762389970577--88999999999999857977988388880133202


Q ss_pred             HHHHCCCCEEEEECCCHHHC--CEEEEEECC---CCCEEEEEHHHHHHHHHHH
Q ss_conf             78748998899986240235--718999989---9978786199999999999
Q gi|254780870|r  394 VADLLGFPLQVIVGSKFVSD--SKVEIKHRL---TGIREDMSLEEVINYASHR  441 (449)
Q Consensus       394 ~Ad~~gip~~iiiG~~el~~--~~Vtir~r~---tg~q~~v~l~eli~~i~~~  441 (449)
T Consensus       542 ~a~~~kiPy~~V~Gd~E~e~~K~~v~vR~~~t~k~~~~~~m~~~E~~~~~~~~  594 (595)
T TIGR00418       542 EAQKQKIPYMLVVGDKEMEELKEAVNVRTRKTLKGQKLEKMSLDEFLEKVRKE  594 (595)
T ss_pred             HHHCCCCCEEEEECCHHHHCCCCEEEECCHHHHCCCCEEEECHHHHHHHHHHC
T ss_conf             20132206799987302313896685224021046310143099999999733