Table 30.3: Classification and subunit structure of aminoacyl-tRNA ­synthetases in E. coli

Class I

Class II

Arg (α)

Ala (α4)

Cys (α)

Asn (α2)

Gln (α)

Asp (α2)

Glu (α)

Gly (α2β2)

IIe (α)

His (α2)

Leu (α)

Lys (α2)

Met (α)

Phe (α2β2)

Trp (α2)

Ser (α2)

Tyr (α2)

Pro (α2)

Val (α)

Thr (α2)