>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=98.83  E-value=8.6e-09  Score=75.00  Aligned_cols=104  Identities=24%  Similarity=0.341  Sum_probs=71.4

Q ss_pred             HHHHHHHHHHHHHHHHHHCCCEEEECCCCCCHHHHHHCCCCHHHHHHHCCHHHCCCCCCEECC--CC----CCCCCCCHH
Q ss_conf             699999999999999986698897357512468987719731122221040213786200034--55----543101100
Q gi|254780870|r   46 GQKALDNVNAIIREEQNRTGAIEMSVPTLQSADLWVESGRYDSYGKEMLRLADRNDKAMIYGP--TH----EEVMTDIFR  119 (449)
Q Consensus        46 G~~i~~~le~~~r~~~~~~G~~ei~tP~l~~~eL~~~SGh~d~~~~em~~~~d~~~~~~~LrP--~~----~e~~~~i~~  119 (449)
T Consensus       150 ~L~lR~~v~~~~Rn~l~~~gFleiETP~LtKsT------------P-------EGARDyLV-PsRv~rsdG~g~FYALp-  208 (653)
T TIGR00459       150 RLKLRHKVTKAVRNFLDQQGFLEIETPILTKST------------P-------EGARDYLV-PSRVHRSDGKGEFYALP-  208 (653)
T ss_pred             HHHHHHHHHHHHHHHHHHCCCCEEECCCCCCCC------------C-------CCHHHCCC-CCCCCCCCCCCCEECCC-
T ss_conf             986688989999866642787065067777888------------4-------31101577-55300368588451468-


Q ss_pred             HCCCCCCCC-----CEEEEECCCCCCCCCCCCCCCCCCEEEEEEECCE-ECCCHHHHHHHH
Q ss_conf             001342013-----4026414653345667675434531668740422-118868879999
Q gi|254780870|r  120 SHIKSYRNL-----PFTFYQIQLKFRDELRPRFGVMRSREFLMKDAYS-FDLTPEGSKHSY  174 (449)
Q Consensus       120 ~~~~SYr~L-----Plr~y~ig~~fR~E~rp~~GL~R~ReF~q~D~~~-F~~~~e~~~~e~  174 (449)
T Consensus       209 QSPQlfKQLLMvsG~drYyQIArCFRDE-DLRAD--RQPEFTQiD~E~SF-~~~~~vm~l~  265 (653)
T TIGR00459       209 QSPQLFKQLLMVSGVDRYYQIARCFRDE-DLRAD--RQPEFTQIDMEMSF-MTQEDVMDLI  265 (653)
T ss_pred             CCHHHHHHHHHHCCCCCCEEEEEEECCC-CCCCC--CCCCCCHHHHHHHC-CCCHHHHHHH
T ss_conf             9756899987512555313578897662-56665--77873244263112-8935689999