背景
The human alanyl-tRNA synthetase (AARS) belongs to a family of tRNA synthases, of the
class II enzymes. Class II tRNA synthases evolved early in evolution and are highly
conserved.This is reflected by the fact that 498 of the 968-residue polypeptide human AARS
shares 41% identity witht the E.coli protein. tRNA synthases are the enzymes that interpret
the RNA code and attach specific aminoacids to the tRNAs that contain the cognate
trinucleotide anticodons.They consist of a catalytic domain which interacts with the amino
acid acceptor-T psi C helix of the tRNA, and a second domain which interacts with the rest of
the tRNA structure.
