>TIGR00435 cysS cysteinyl-tRNA synthetase; InterPro: IPR002308 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 . Cysteinyl-tRNA synthetase (6.1.1.16 from EC) is an alpha monomer and belongs to class Ia.; GO: 0000166 nucleotide binding, 0004817 cysteine-tRNA ligase activity, 0005524 ATP binding, 0006412 translation, 0006423 cysteinyl-tRNA aminoacylation, 0005737 cytoplasm.

Probab=99.52 E-value=1.6e-14 Score=124.57 Aligned_cols=163 Identities=18% Similarity=0.265 Sum_probs=116.6 Q ss_pred CCCCCCCCCCCCCCHHHHHHHHHHHCCCCCCCCCCCCCCHHCCCC-CCCCHHHHHHHHHCCCCCCHHHHHC-CCCHHHHH Q ss_conf 553012455432101356777665301211337868520000144-3100012255431245653023320-25403444 Q gi|254780933|r 539 PTSVLVTGFDILFFWVARMMMMGLYFMKDAEGKGIEPFHIVYMHA-LVRDKNGQKMSKSKGNVVDPIDVID-QYGADALR 616 (947) Q Consensus 539 P~d~~~~G~Di~r~W~~~~l~~~~~l~~~~~~~~~~Pfk~v~~hG-~vld~~G~KMSKS~GNvidp~e~i~-~yGaDalR 616 (947) T Consensus 366 ~~DIH~GG~DL~FPHHENE~Aqs~a~~------gn~~~~~yW~H~G~~~-id~eKMSKSLgNF~~v~D~L~q~~d~~~lR 438 (660) T TIGR00435 366 QIDIHGGGVDLIFPHHENEIAQSEALF------GNKQLAKYWLHNGFLM-IDNEKMSKSLGNFITVRDVLKQNYDPEVLR 438 (660) T ss_pred CCEECCCCCCCCCCCCHHHHHHHHHHH------CCCCEEEEEEECCEEE-ECCCCCCHHHHHHHHHHHHHHCCCCHHHHH T ss_conf 430134887788878778999999872------8985689998517789-767216515556888886874276899999 Q ss_pred HHHHCCCCCCCCCCCCCCCCCCCH---HHHHHHHHHHHHHHCCCCCC-CCCCCCCCCCCHHHHHHHHHHHHHHHHHHHHH Q ss_conf 543123355677543411011100---00123444333320244457-76767743331555677999999998889987 Q gi|254780933|r 617 FYFSIMAVQGRDINLDLERIAGYR---NFITKFWNAIRFSKMKNARH-SVSFVPQDVKWIVNKWIIKRLATVINDVTVGM 692 (947) Q Consensus 617 ~~l~~~~~~~~D~~fs~~~i~~~r---~f~nKLwNa~rf~~~~~~~~-~~~~~~~~~~~~~Drwils~l~~~i~~v~~~~ 692 (947) T Consensus 439 ~~~l~~HYr-~pLdf~e~~l~~aksfe~~~~~l~~~l~~~~~~~~~~~~~~~~~~~-~~~~~~~~~~~F~Eseskvhsa~ 516 (660) T TIGR00435 439 YLLLSVHYR-SPLDFSEELLEAAKSFENALERLYKALRNLDTDLAYSKEFGENKDP-KNVDEKEFEAAFEESESKVHSAM 516 (660) T ss_pred HHHHHHHHC-CCCCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCCCCCCCCC-CCCHHHHHHHHHHHHHHHHHHHH T ss_conf 998765531-4567478899999889999999999999875310342223424356-64225657866432035778887 Q ss_pred -HHHCCCHHHHHHHHHHHC Q ss_conf -531001024577765310 Q gi|254780933|r 693 -ENHRFNDVSAVLYRFVWD 710 (947) Q Consensus 693 -e~~~f~~a~~~i~~F~~~ 710 (947) T Consensus 517 ~dDlN~a~Al~vL~el~~~ 535 (660) T TIGR00435 517 DDDLNTANALAVLFELAKS 535 (660) T ss_pred HHCCCHHHHHHHHHHHHHH T ss_conf 5057806899999999998

HHsearch alignment for GI: 254780933 and conserved domain: TIGR00435