>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=99.65 E-value=4.1e-16 Score=129.71 Aligned_cols=161 Identities=22% Similarity=0.280 Sum_probs=118.4 Q ss_pred CCCCCCCCCCCCCCHHHHHH---HHHHHHCCC-CCEEEEECCC-CCEECCCCCCHHCCCCCCCCHHHHHC-CCCHHHHHH Q ss_conf 44310025544421112455---444331178-4000013037-82621345300001234433366411-367578878 Q gi|254780445|r 585 WPADVYLEGSDQHRGWFQHS---LLESCATRG-STPFTSLITH-GFSVDENGEKMSKSKGNVVFPEEIIS-ESGADVLRY 658 (963) Q Consensus 585 ~PaD~~~eG~Dq~RgWF~s~---ll~~~~~~~-~~Pfk~v~~h-G~vld~~G~KMSKS~GNvi~p~~ii~-~yGaD~lR~ 658 (963) T Consensus 365 ~~~DIH~GG~DL~---FPHHENE~Aqs~a~~gn~~~-~~yW~H~G~~~-id~eKMSKSLgNF~~v~D~L~q~~d~~~lR~ 439 (660) T TIGR00435 365 DQIDIHGGGVDLI---FPHHENEIAQSEALFGNKQL-AKYWLHNGFLM-IDNEKMSKSLGNFITVRDVLKQNYDPEVLRY 439 (660) T ss_pred CCCEECCCCCCCC---CCCCHHHHHHHHHHHCCCCE-EEEEEECCEEE-ECCCCCCHHHHHHHHHHHHHHCCCCHHHHHH T ss_conf 5430134887788---87877899999987289856-89998517789-7672165155568888868742768999999 Q ss_pred HHHHCCCCCCCCCCCHHHHHHH---HHHHHHCCCCCCCCCCCCCCCCCCCCHHHHHHHHHHHHHHHHHHHHHHHHHH-HH Q ss_conf 8871787665544310256777---6400000110000012244445673101112788875436899999988987-65 Q gi|254780445|r 659 WAVNSDYHDDQRLGKNIIQTNI---DTYRKLRNTIRWMLGMLAHDTGNEPSLADMPALEQLMLHRLTELDQVVREAY-DA 734 (963) Q Consensus 659 ~~~~~~~~~d~~~~~~~l~~~~---~~~~kl~Nt~rf~l~~l~~~~~~~~~~~~l~~~DkwiLskl~~~i~~v~~~~-e~ 734 (963) T Consensus 440 ~~l~~HYr~pLdf~e~~l~~aksfe~~~~~l~~~l~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~F~Eseskvhsa~~dD 519 (660) T TIGR00435 440 LLLSVHYRSPLDFSEELLEAAKSFENALERLYKALRNLDTDLAYSKEFGENKDPKNVDEKEFEAAFEESESKVHSAMDDD 519 (660) T ss_pred HHHHHHHCCCCCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCCCCCCCCCCCCHHHHHHHHHHHHHHHHHHHHHHC T ss_conf 98765531456747889999988999999999999987531034222342435664225657866432035778887505 Q ss_pred HHHHHHHHHHHHHHHH Q ss_conf 4012266889987863 Q gi|254780445|r 735 FNFKEVVRQLTNFSNA 750 (963) Q Consensus 735 ~~f~~a~~~i~~F~~~ 750 (963) T Consensus 520 lN~a~Al~vL~el~~~ 535 (660) T TIGR00435 520 LNTANALAVLFELAKS 535 (660) T ss_pred CCHHHHHHHHHHHHHH T ss_conf 7806899999999998

HHsearch alignment for GI: 254780445 and conserved domain: TIGR00435