HHsearch alignment for GI: 254780680 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=99.82  E-value=1.5e-20  Score=173.53  Aligned_cols=355  Identities=19%  Similarity=0.258  Sum_probs=244.7

Q ss_pred             HHHHHHHHHHHHHHHHHHHHHHHHHHHHC-CCHHHHHHHHH-HHHHHHHHHHHH---HHHHHHH--HHH-HHHHH--HHC
Q ss_conf             99999999999999999999999998644-99879999999-999999886444---6666677--888-77443--100
Q gi|254780680|r   36 KNRILIKKIEDIRARRNSNSAQIGQAIAE-GNLSLVDALKN-ETSTLKEQLPIL---EKEEHEV--CSS-LKKLI--SCI  105 (430)
Q Consensus        36 ~rr~l~~e~e~LraerN~lSKeIg~~k~~-~~~~~~~~Lk~-e~~~Lk~eik~l---e~~~~~l--e~e-l~~ll--l~I  105 (430)
T Consensus        38 ~~~~~~~dl~~ie~~m~~~~~~~~~~~~~~~s~~~A~~~f~~~~~~~k~~l~~~~~~~~~~~~~y~~~~~f~dlC~GpHl  117 (595)
T TIGR00418        38 DKSITEEDLEKIEKEMKEIIKKNYPIARLSVSLEEALEAFKEVGEPLKLELLDEIIPNGEAVTVYGQGEAFVDLCRGPHL  117 (595)
T ss_pred             CHHCCHHHHHHHHHHHHHHHHHHCCEEEEEECHHHHHHHHHHHCCHHHHHHHHHCCCCCCCEEEECCCCEEEECCCCCCC
T ss_conf             00027789999999999998640570257724789999998621312267785104566642042252134561579768


Q ss_pred             CCCCCCHHHH-------------CCCCCCCEEEEEEC--CCCCCC--------------CCCC--CCCCHHHHCCCCCHH
Q ss_conf             2258811221-------------13555402420001--565665--------------6662--112202211731000
Q gi|254780680|r  106 PNVPLEEVPI-------------GTSANENILIRSVG--KKPSAI--------------HLSR--EHFEIGEALGLMDFD  154 (430)
Q Consensus       106 PNi~~~~VP~-------------G~de~dNv~i~~~G--~~~~f~--------------f~~k--~H~elge~l~liDfe  154 (430)
T Consensus       118 p~~~~~~~~~~~fkL~~~~gaYw~Gd~~n~~LqRiyGn~~~~~~~~k~~L~~yl~~~eEa~~r~PDHRklGKeL~Lf~f~  197 (595)
T TIGR00418       118 PNTSRIKPAQKAFKLEKVAGAYWRGDSKNEMLQRIYGNIDITAFADKKQLAEYLKRLEEAKKREPDHRKLGKELELFSFE  197 (595)
T ss_pred             CCCCCCCCCCHHHHHHHHHHHHHCCCCCCCEEEEECCCEEEECCCCHHHHHHHHHHHHHHHCCCCCHHHHHHHHCCCCCC
T ss_conf             32356676403456654323310268898537888572545014587899999999999742685725675453123458


Q ss_pred             HHHHHCCCCCEEECCHHHHHHHHHHHHHHHHHHHHCCCCEEHHHHHCCHHHHHHHHHCHHHHHHHHH-HH---HCCEECC
Q ss_conf             1122216753010564889999999999986223203202123562027889865514224767764-31---0002313
Q gi|254780680|r  155 RATKLSGARFSVLTGHLAHLERALGQFMIDLHTSEHGYTEVSAPLLVRDEAMYGTGQIPKFADDMFC-TT---DGRWLIP  230 (430)
Q Consensus       155 ~a~kvsGsrF~~Lkg~~A~Le~ALi~y~ld~~~~~~Gy~~v~~P~lv~~~~~~gtG~lp~f~~~~y~-~~---d~l~Li~  230 (430)
T Consensus       198 ~~---~gpG~~~WlPkG~~ir~~ledf~~~~~-~~~Gy~~V~TP~m~~~~l~~~sGH~~~Y~e~Mf~~~~~~~~~~~LkP  273 (595)
T TIGR00418       198 PE---IGPGLPFWLPKGALIRNLLEDFVREKQ-IKRGYEEVETPIMYDSELWEISGHWDHYKERMFPFTEEDNQEFMLKP  273 (595)
T ss_pred             CC---CCCCCEEECCCHHHHHHHHHHHHHHHH-HHCCCCCCCCCEECCCCCHHHHHHHHHCCCCCCCCEEECCCCCCCCC
T ss_conf             32---048741465764678999999999999-87588641574121565424530545034235401010353033456


Q ss_pred             CCCCHHHHHHHHHCCCHHHHCCEEEEEE-CCCCCCC-CCCCCCCCCEEEEEEEEEEEEEECCC-CCCHHHHHHHHHHHHH
Q ss_conf             4541145445342059555042088532-2107884-33554343212222102002121278-6501457898999999
Q gi|254780680|r  231 TSEVSLTNLYSHEIIESKSLPLRFTTLA-PSFRSEA-GSAGRDTRGMLRQHQFWKCELVSITR-EEDSFTEHERMLSCAE  307 (430)
Q Consensus       231 TaEvpL~~~~~~~~l~~~~LPik~~~~s-~cfR~Ea-Gs~GkdtrGl~RvHQF~KVE~~~~~~-pe~S~~~~e~~~~~~~  307 (430)
T Consensus       274 MnCpgH~~i~k~~~~SYR~LP~R~aE~g~~~hR~E~sG~----L~GL~RvR~FT~dDaHifc~d~dQi~~E~~~~~~l~~  349 (595)
T TIGR00418       274 MNCPGHILIFKSSLRSYRDLPLRIAELGTTVHRYEKSGA----LHGLKRVRGFTQDDAHIFCTDEDQIKSEIKNQFRLIQ  349 (595)
T ss_pred             CCCHHHHHHHCCCCCCHHHCCCHHHHCCCEEEEEECCCC----CCHHHHHHHCCCCCCCEEECCHHHHHHHHHHHHHHHH
T ss_conf             775445330017777732335034331860478842542----1010164430699852453786779999999999999


Q ss_pred             HHHHHHCCHHHHCCCCCHHCCCHHHEEE--EEEEECCCC--------------------CCE--------------EEEE
Q ss_conf             9999841067530378011784434024--101101004--------------------833--------------2375
Q gi|254780680|r  308 EILKRLDLHYRVVSLCTGDLGFSACKTY--DLEVWLAGQ--------------------NLY--------------REIS  351 (430)
Q Consensus       308 ~i~~~L~lpyRvv~~~sgdlg~~a~~~~--DiE~w~P~~--------------------~~y--------------~Ev~  351 (430)
T Consensus       350 ~v~~~fgf~~~~~~LS~R~Pe~--~~Ky~g~d~~W~~~~~~l~~~l~~~~~~yei~~G~~AFYGPKiDf~~~DaL~R~~q  427 (595)
T TIGR00418       350 KVYSKFGFSNYKYELSTRDPEN--DKKYIGEDELWEKAESALEEALKELGVDYEIDEGEGAFYGPKIDFQIKDALGREWQ  427 (595)
T ss_pred             HHHHHHCCCCCEEEEEECCCCC--CCCCCCCHHHHHHHHHHHHHHHHCCCCCEEEECCCCEEECCEEEEEEEECCCCHHH
T ss_conf             9988728842168998717775--45545887899999999999985079840550788113022268887510176425


Q ss_pred             EECCCCCHHH-HHCCCEEECCC--CCCCCEEEEECCCHH-HHHHHHHHHHHHCC
Q ss_conf             3102100764-53268473389--984101042004322-89999999988346
Q gi|254780680|r  352 SCSTCGNFQS-RRMNSRYRDPN--SKSLKFTHTLNGSGV-AVGRCLIAILENYL  401 (430)
Q Consensus       352 S~Snc~D~Qs-rRl~iry~~~~--~~~~~~~htlNgt~~-A~~R~l~ailEn~q  401 (430)
T Consensus       428 ~~TvQlDf~lPeRF~l~Y~~~dqd~~~-~~Pv~IHra~~GS~ERfi~iL~E~~~  480 (595)
T TIGR00418       428 CATVQLDFELPERFDLTYINEDQDNKE-KRPVMIHRAILGSIERFIAILLEKYA  480 (595)
T ss_pred             CCCEEEECCCCCCCCCEEEEECCCCCC-CCCEEEECCCCHHHHHHHHHHHHHHH
T ss_conf             881488715887203148420367870-06778980440058999999998752