>TIGR02432 lysidine_TilS_N tRNA(Ile)-lysidine synthetase; InterPro: IPR012795 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 . The only examples in which the wobble position of a tRNA must discriminate between G and A of mRNA are AUA (Ile) vs. AUG (Met) and UGA (stop) vs. UGG (Trp). In all bacteria, the wobble position of the tRNA(Ile) recognizing AUA is lysidine, a lysine derivative of cytidine. This domain is found, apparently, in all bacteria in a single copy. Eukaryotic sequences appear to be organellar. The domain architecture of this protein is variable; some, including characterised proteins of Escherichia coli and Bacillus subtilis known to be tRNA(Ile)-lysidine synthetase, include a conserved 50-residue domain that many other members lack. This protein belongs to the ATP-binding PP-loop family. It appears in the literature and protein databases as TilS, YacA, and putative cell cycle protein MesJ (a misnomer).; GO: 0000166 nucleotide binding, 0005524 ATP binding, 0016879 ligase activity forming carbon-nitrogen bonds, 0008033 tRNA processing, 0005737 cytoplasm.

Probab=99.31 E-value=1.8e-11 Score=102.70 Aligned_cols=167 Identities=20% Similarity=0.275 Sum_probs=112.7 Q ss_pred EEEEEECCCHHHHHHHHHHHH----CCCE-------EEEEEEECCCCCCCCCCCCCCCCHH-HHHHHHHHHHHCCCCEEE Q ss_conf 899996098579999999988----6984-------9999987047876655557788189-999999999980995898 Q gi|254780151|r 22 RVVVAMSGGVDSSVVAALLKR----DGYD-------VIGVTLQLYNSRKASKRKGSCCAGQ-DVYDARRVCDTINVSHYV 89 (408) Q Consensus 22 kV~va~SGGVDSsvaa~lL~~----~G~~-------V~g~~m~~~~~~~~~~~~~~c~~~~-d~~~a~~va~~LgI~~~~ 89 (408) T Consensus 1 ~~lvAvSGG~DS~aLL~~L~~~~~~~~~~~~~~~~~~~a~h~-nH~lR-------~-~s~~~~~~~v~~~c~~~~~~~~~ 71 (204) T TIGR02432 1 KILVAVSGGVDSMALLHLLLKLQPKLKISWQIKDFKLIAAHV-NHGLR-------P-ESAQEEAEFVQQFCEKLNIPLEI 71 (204) T ss_pred CEEEEEECCHHHHHHHHHHHHHHHHCCCCCCCCCEEEEEEEE-ECCCC-------H-HHHHHHHHHHHHHHHHCCCCEEE T ss_conf 978886286427999999999766327877887506899996-17788-------4-15899999999999961895699 Q ss_pred CC-HHHH-HHHHCCCCCHHHHHCCCCCCCEECCCCEEEHHHHHHHHCCCC-CCEECCCCCCC--EEEECCCCCCCEEEEE Q ss_conf 17-0788-663224411267870886120000154110588888740168-76452253110--2541267877316885 Q gi|254780151|r 90 FD-YEER-FRNAVIVPFASSYAAGETPLPCVDCNRTVKFSDLLSVTRQLG-ADVLATGHYIR--SRLYVGDDGKRRRIMC 164 (408) Q Consensus 90 ~d-~~~~-f~~~V~~~~~~~y~~G~TPNPc~~CN~~iKF~~l~~~a~~~g-~~~iATGHYar--~~~~~~~~~~~~~~L~ 164 (408) T Consensus 72 ~~~~~~~~~~~~~~~~-~E~~A------------R~~RY~~f~~~~~~~~~~~~i~tAHh~dDq~ET~-------L~rL~ 131 (204) T TIGR02432 72 KKLVDVKALAKGKKKN-LEEAA------------REARYAFFEEIAKKHGKADYILTAHHADDQAETI-------LMRLL 131 (204) T ss_pred EEEECCCCCCCCCCCC-HHHHH------------HHHHHHHHHHHHHHCCCCEEEEECCCCCCHHHHH-------HHHHH T ss_conf 8421241101224767-78999------------9999999999999729940899724832279999-------99875 Q ss_pred ECCCCCCCCEEEEEEECCHH---------HCEEECCCCCCCHHHHHHHHHHCCCCCCCHHHCCCEEE Q ss_conf 31578787318986302022---------10033425689978989999741254355111023011 Q gi|254780151|r 165 RPMDLERDQSYFLFATTQQQ---------LCDLRFPLGDMKKESVRDLAREMGLDIADKSDSQDICF 222 (408) Q Consensus 165 r~~D~~KDQSYfL~~l~~~~---------L~~~~FPlg~~~K~eVR~~A~~~gl~~a~K~eSqgICF 222 (408) T Consensus 132 RG~~~~G-----l~g~~~~~~~~~~g~~~~~~~~RPLL~~~k~ei~~y~~~~~l~~~eD~tN~~~~y 193 (204) T TIGR02432 132 RGSGLRG-----LSGMPEIRPLGSLGWYKGGQIIRPLLNISKSEIEEYLKENGLPYFEDETNQDDKY 193 (204) T ss_pred HCCCCCH-----HHHHCCCCCCCCCCCCCCEEEEECCCCCCHHHHHHHHHHCCCCEEECCCCCCCCC T ss_conf 1687000-----1110133663324422563277077567789999999966896565788898762

HHsearch alignment for GI: 254780151 and conserved domain: TIGR02432