leucine--tRNA ligase; LeuRS; class-I aminoacyl-tRNA synthetase; charges leucine by linking carboxyl group to alpha-phosphate of ATP and then transfers aminoacyl-adenylate to its tRNA; due to the large number of codons that tRNA(Leu) recognizes, the leucyl-tRNA synthetase does not recognize the anticodon loop of the tRNA, but instead recognition is dependent on a conserved discriminator base A37 and a long arm; an editing domain hydrolyzes misformed products; in Methanothermobacter thermautotrophicus this enzyme associates with prolyl-tRNA synthetase (857 aa)

Aminomethyltransferase; The glycine cleavage system catalyzes the degradation of glycine (367 aa)

Glutamyl-tRNA(Gln) amidotransferase subunit A; Allows the formation of correctly charged Gln-tRNA(Gln) through the transamidation of misacylated Glu-tRNA(Gln) in organisms which lack glutaminyl-tRNA synthetase. The reaction takes place in the presence of glutamine and ATP through an activated gamma-phospho-Glu-tRNA(Gln) (486 aa)

Translation initiation factor IF-2; One of the essential components for the initiation of protein synthesis. Protects formylmethionyl-tRNA from spontaneous hydrolysis and promotes its binding to the 30S ribosomal subunits. Also involved in the hydrolysis of GTP during the formation of the 70S ribosomal complex (650 aa)

Phenylalanine--tRNA ligase beta subunit; Catalyzes a two-step reaction, first charging a phenylalanine molecule by linking its carboxyl group to the alpha-phosphate of ATP, followed by transfer of the aminoacyl-adenylate to its tRNA; forms a tetramer of alpha(2)beta(2); binds two magnesium ions per tetramer; type 2 subfamily; Belongs to the phenylalanyl-tRNA synthetase beta subunit family. Type 1 subfamily (814 aa)

Elongation factor 4; Required for accurate and efficient protein synthesis under certain stress conditions. May act as a fidelity factor of the translation reaction, by catalyzing a one-codon backward translocation of tRNAs on improperly translocated ribosomes. Back- translocation proceeds from a post-translocation (POST) complex to a pre-translocation (PRE) complex, thus giving elongation factor G a second chance to translocate the tRNAs correctly. Binds to ribosomes in a GTP-dependent manner (606 aa)

Valine--tRNA ligase; Catalyzes the attachment of valine to tRNA(Val). As ValRS can inadvertently accommodate and process structurally similar amino acids such as threonine, to avoid such errors, it has a "posttransfer" editing activity that hydrolyzes mischarged Thr-tRNA(Val) in a tRNA-dependent manner; Belongs to the class-I aminoacyl-tRNA synthetase family. ValS type 1 subfamily (914 aa)

Isoleucine--tRNA ligase; Catalyzes the attachment of isoleucine to tRNA(Ile). As IleRS can inadvertently accommodate and process structurally similar amino acids such as valine, to avoid such errors it has two additional distinct tRNA(Ile)-dependent editing activities. One activity is designated as ’pretransfer’ editing and involves the hydrolysis of activated Val-AMP. The other activity is designated ’posttransfer’ editing and involves deacylation of mischarged Val-tRNA(Ile); Belongs to the class-I aminoacyl-tRNA synthetase family. IleS type 1 subfamily (974 aa)