>TIGR00442 hisS histidyl-tRNA synthetase; InterPro: IPR015807 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 . Histidyl-tRNA synthetase (6.1.1.21 from EC) is an alpha2 dimer that belongs to class IIa. Every completed genome includes a histidyl-tRNA synthetase. Apparent second copies from Bacillus subtilis, Synechocystis sp., and Aquifex aeolicus are slightly shorter, more closely related to each other than to other hisS proteins, and not demonstrated to act as histidyl-tRNA synthetases (see IPR004517 from INTERPRO). The regulatory protein kinase GCN2 of Saccharomyces cerevisiae (YDR283c), and related proteins from other species designated eIF-2 alpha kinase, have a domain closely related to histidyl-tRNA synthetase that may serve to detect and respond to uncharged tRNA(his), an indicator of amino acid starvation, but these regulatory proteins are not orthologous.; GO: 0000166 nucleotide binding, 0004821 histidine-tRNA ligase activity, 0005524 ATP binding, 0006412 translation, 0006427 histidyl-tRNA aminoacylation, 0005737 cytoplasm.

Probab=100.00 E-value=0 Score=489.02 Aligned_cols=429 Identities=31% Similarity=0.532 Sum_probs=362.3 Q ss_pred CCCCCCCCCCCCCHHHHHHHHHHHHHHHHHHHHCCCEEEECCCHHHHHHHHC-CCCCCCCCCCCEEEEECCCCCEEEECC Q ss_conf 7103799876588668999999999999999985984801652022887520-267554333221689869998899988 Q gi|254780928|r 7 LRAELPRGFADCPTKEIRIRNRILDSIRNIYENYGFDPIETPLLEYSDSLGK-FLPDEDRPNKGVFSLQDDDGQWISLRY 85 (496) Q Consensus 7 ~~~~~P~G~~D~~p~~~~~~~~i~~~l~~~f~~~G~~~I~tP~lE~~~~~~~-~~~~~~~~~k~~y~f~D~~g~~l~LRp 85 (496) T Consensus 2 ~~~~~~~G~~d~~p~~~~~~~~~~~~~~~~~~~~g~~~~~~P~~e~~~~~~~~~~~~~~~~~~~~y~f~d~~~~~~~lrp 81 (446) T TIGR00442 2 VDLQKPRGTKDWLPGELVYRQWIEAKLRSVLESYGYSEIRTPIFEYTELFARGIGKSGDEVEKELYTFKDKGGRDLALRP 81 (446) T ss_pred CCCCCCCCCCCCCCHHHHHHHHHHHHHHHHHHHCCCCCCCCCHHHHHHHHHHHCCCCHHHHHHHHEEEECCCCCEEEECC T ss_conf 76323455200254157899999999999997517720012114445666530253013344443012127884144222 Q ss_pred CCHHHHHHHHHHHHHHC--CCCHHHHHHHHHHCCCCCC-CCCCCCCCCCCHHHHHCCCHHHHHHHHHHHHHHHHHCCCCC Q ss_conf 88389999999511205--5411233101333025876-44421111100012100002457889999999997518887 Q gi|254780928|r 86 DLTAPLARYVAENFDTI--VFPCRTYRIGPVFRNEKHG-PGRFRQFIQCDVDNVGSSAETADAEMCMMMADTLEAVGIKR 162 (496) Q Consensus 86 DlT~~~aR~~~~~~~~~--~~p~k~yy~g~vfR~e~p~-~Gr~REf~Q~g~eiiG~~~~~~DaEii~l~~~~l~~lgl~~ 162 (496) T Consensus 82 ~~t~~~~r~~~~~~~~~~~~~p~~~~~~g~~~r~e~p~~~gr~r~f~~~~~~~~G~~~~~~~~~~~~~~~~~~~~~g~~- 160 (446) T TIGR00442 82 ELTAPVVRLVAENKLLLPANKPLRLYYIGPVFRYERPQLKGRYREFWQFGCEVIGSESPLADAEVLSLAVEGLKALGLE- 160 (446) T ss_pred CHHHHHHHHHHHHHHHCCCCCCEEEEEEECHHHCCCHHHHCCHHHHHHCCEEEECCCCCHHHHHHHHHHHHHHHHHCCC- T ss_conf 0036899999875431046764243232010102241230101133211504643665203689999999989860766- Q ss_pred CC-CEEECCCCHHHHHHHHHHCCCHHHHHHHHHHHHHHHHHCCCCCHHHHHHHHHHCCCCHHHHHHCCCCCCHHHHHHHH Q ss_conf 77-11303660558999998325603564334555333220012896789986210165003555304899977899888 Q gi|254780928|r 163 ND-YHIGINNRKILDGILEKIGLHGDDKLNERLIVLRAIDKLDKFGLQGVKLLLGEGRTDNSGDFTKGANLTSEQIDIMV 241 (496) Q Consensus 163 ~~-~~I~in~~~il~~il~~lgi~~~~~~~~~~~~~~~idkl~k~~~~~~~~~l~~~~~~~~~~~~~~~~~~~~~~~~~~ 241 (496) T Consensus 161 -~~~~~~~~~~g~~~~~~~~~~~~~~~-----~~~~~~~~~~~~~~~~~~~~~~~~-----------~~~~~~~~~~~~~ 223 (446) T TIGR00442 161 -GHFKLKLNHLGILEGILEYRGALEED-----VYLTPIKDKLDKDDQERLEEELTN-----------PLRILDEKVDELL 223 (446) T ss_pred -CEEEEEECCCHHHHHHHHHHCCHHHH-----HHHHHHHHHHCCCHHHHHHHHHHH-----------HHHHHHHHHHHHH T ss_conf -32788741300145666652110234-----566566666230115678998765-----------4432122245677 Q ss_pred HHHCCC-CHHHHHHHHHHHCCCHHHHHHHHHHHHHHHHHHHCCCCCCCCCCCHHHCCCCCCCCCEEEEEEECCCCCCCCC Q ss_conf 740478-5688998998603573258889999999999875088844300110100122123412489985466677676 Q gi|254780928|r 242 SFLSID-LEKSMHELYELVKGTIAGEKGFNELVVISELVRKSGYNSNRIKISSTIVRGLEYYTGCVYEAILGFPVMNEKQ 320 (496) Q Consensus 242 ~~~~~~-~~~~~~~l~~~~~~~~~~~~~l~~l~~i~~~l~~~gv~~~~i~~Dl~lvRgLdYYTG~vFE~~~~~~~~~~~~ 320 (496) T Consensus 224 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~l~~~~~~~-~~~~~~~~~rGldyy~g~~~e~~~~-------- 294 (446) T TIGR00442 224 ELLKLKGAPEILDYLDELLDESEGHFEGLKDLEELFQLLEDLGIDD-LYELNLGLARGLDYYTGTVFEIVTN-------- 294 (446) T ss_pred HHHHCCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCC-EEEECCHHHHHHHHHCCEEEEEECC-------- T ss_conf 7763256225788888874123578889989999999986505421-0220511331001111323443101-------- Q ss_pred CCCCEEEECCCCCCCCCCCCCCCCCCCCCEEEECCHHHHHHHHHCCCCCCCCCCCC-EEEEEEECCCHHHHHHHHHHHHH Q ss_conf 66310110032323552111234567742133110168999997368776655577-14899826976899999999999 Q gi|254780928|r 321 KPVVFGSVGGGGRYDGLVSRFKGQNVPATGFSIGISRLIVALKSLESSTNNIKEMG-PVLITTMDHDSDSLSKYQMYTQM 399 (496) Q Consensus 321 ~~~~~~aI~~GGRYD~L~~~f~~~~~pavGfaigverl~~~l~~~~~~~~~~~~~~-~v~V~~~~~~~~~~~~~~~ia~~ 399 (496) T Consensus 295 ~~~~~~~~~~GG~yd~l~~~~~~~~~~~~G~~~g~~r~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 374 (446) T TIGR00442 295 ALGAQGTVCGGGRYDNLVEEFGGPPTPAVGFAFGLERLINLLDAEKPSFPLAKVVDARVFVLVVGLGEEALPEALRLAEK 374 (446) T ss_pred CCCCCCCEECCCCHHHHHHHHCCCCCCCCHHHHHHHHHHHHHHHHHHHHCCCCCCCCEEEEEEEECCHHHHHHHHHHHHH T ss_conf 12432100046510125665067545410023308999998756543100001111102577860642457899999999 Q ss_pred HHHC--CCEEEEEEC-CCCCHHHHHHHHHHCCCCEEEEECHHHHHCCCEEEEECCCC-CEEEEECCC Q ss_conf 9987--983999718-99998899999987799899998872874881899787888-364331120 Q gi|254780928|r 400 LRTA--GIRAEMFLG-SSKNFGNQLKYADRRNCPLAIIQGTGERSRGMLQIKDLAKG-KELSREIKN 462 (496) Q Consensus 400 Lr~~--Gi~~e~~~~-~~~sl~~~~~~A~~~g~~~viiig~~e~~~~~v~vK~l~~g-~q~~~~~~~ 462 (496) T Consensus 375 ~~~~~~g~~~~~~~~~~~~~~~~~~~~a~~~g~~~~~~~G~~~~~~~~~~~k~~~~~~~~~~~~~~~ 441 (446) T TIGR00442 375 LREALPGISAELYPKNNGRKLKKQFSYADKLGARFAVVLGEEELKEGKVTVKDLETGFEQTTLALDE 441 (446) T ss_pred HHHHCCCCEEEEEECCCCHHHHHHHHHHHHCCCEEEEEECCCCCCCCCEEEHHHHHHHHHHHHHHHH T ss_conf 9873378516885221100134555456434854899845310013412201223124567775787

HHsearch alignment for GI: 254780928 and conserved domain: TIGR00442