>TIGR00459 aspS_bact aspartyl-tRNA synthetase; InterPro: IPR004524 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 . Aspartyl tRNA synthetase 6.1.1.12 from EC is an alpha2 dimer that belongs to class IIb. Structural analysis combined with mutagenesis and enzymology data on the yeast enzyme point to a tRNA binding process that starts by a recognition event between the tRNA anticodon loop and the synthetase anticodon binding module . This family represents aspartyl-tRNA synthetases from the bacteria and from mitochondria. In some species, this enzyme aminoacylates tRNA for both Asp and Asn; Asp-tRNA(asn) is subsequently transamidated to Asn-tRNA(asn). ; GO: 0000166 nucleotide binding, 0004815 aspartate-tRNA ligase activity, 0005524 ATP binding, 0006412 translation, 0006422 aspartyl-tRNA aminoacylation, 0005737 cytoplasm.

Probab=98.70  E-value=6.1e-08  Score=70.74  Aligned_cols=104  Identities=28%  Similarity=0.501  Sum_probs=76.3

Q ss_pred             HHHHHHHHHHHHHHHHHHHHCCCEEEECCCHHHHHHHHCCCCCCCC----CCCCEEEEECCCCCEEEECCCCHHHHHHHH
Q ss_conf             6689999999999999999859848016520228875202675543----332216898699988999888838999999
Q gi|254780928|r   20 TKEIRIRNRILDSIRNIYENYGFDPIETPLLEYSDSLGKFLPDEDR----PNKGVFSLQDDDGQWISLRYDLTAPLARYV   95 (496)
Q Consensus        20 p~~~~~~~~i~~~l~~~f~~~G~~~I~tP~lE~~~~~~~~~~~~~~----~~k~~y~f~D~~g~~l~LRpDlT~~~aR~~   95 (496)
T Consensus       148 ~~~L~lR~~v~~~~Rn~l~~~gFleiETP~L------tKsTPEGARDyLVPsR-v-~rsdG~g~FYALp--QSPQlfKQL  217 (653)
T TIGR00459       148 QQRLKLRHKVTKAVRNFLDQQGFLEIETPIL------TKSTPEGARDYLVPSR-V-HRSDGKGEFYALP--QSPQLFKQL  217 (653)
T ss_pred             HHHHHHHHHHHHHHHHHHHHCCCCEEECCCC------CCCCCCCHHHCCCCCC-C-CCCCCCCCEECCC--CCHHHHHHH
T ss_conf             9998668898999986664278706506777------7888431101577553-0-0368588451468--975689998


Q ss_pred             HHHHHHCCCCHHHHHHHHHHCCCCCCCCCCCCCCCCCHHHHH
Q ss_conf             951120554112331013330258764442111110001210
Q gi|254780928|r   96 AENFDTIVFPCRTYRIGPVFRNEKHGPGRFRQFIQCDVDNVG  137 (496)
Q Consensus        96 ~~~~~~~~~p~k~yy~g~vfR~e~p~~Gr~REf~Q~g~eiiG  137 (496)
T Consensus       218 LMv-sG~---drYyQIArCFRDEDLRADRQPEFTQiD~E~SF  255 (653)
T TIGR00459       218 LMV-SGV---DRYYQIARCFRDEDLRADRQPEFTQIDMEMSF  255 (653)
T ss_pred             HHH-CCC---CCCEEEEEEECCCCCCCCCCCCCCHHHHHHHC
T ss_conf             751-255---53135788976625666577873244263112