AARS siRNA – Alanine--Trna Ligase, Cytoplasmic (Human)

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. [provided by RefSeq, Jul 2008]

AARS: Catalyzes the attachment of alanine to tRNA(Ala) in a two-step reaction: alanine is first activated by ATP to form Ala- AMP and then transferred to the acceptor end of tRNA(Ala). Also edits incorrectly charged tRNA(Ala) via its editing domain. Defects in AARS are the cause of Charcot-Marie-Tooth disease type 2N (CMT2N). It is an axonal form of Charcot-Marie-Tooth disease, a disorder of the peripheral nervous system, characterized by progressive weakness and atrophy, initially of the peroneal muscles and later of the distal muscles of the arms. Charcot-Marie-Tooth disease is classified in two main groups on the basis of electrophysiologic properties and histopathology: primary peripheral demyelinating neuropathies(designated CMT1 when they are dominantly inherited) and primary peripheral axonal neuropathies (CMT2). Neuropathies of the CMT2 group are characterized by signs of axonal regeneration in the absence of obvious myelin alterations, normal or slightly reduced nerve conduction velocities, and progressive distal muscle weakness and atrophy. Nerve conduction velocities are normal or slightly reduced. Belongs to the class-II aminoacyl-tRNA synthetase family.

Protein type: Translation; Ligase; RNA-binding; EC 6.1.1.7

Chromosomal Location of Human Ortholog: 16q22

Cellular Component: membrane; cytoplasm; cytosol

Molecular Function: amino acid binding; zinc ion binding; alanine-tRNA ligase activity; ATP binding; tRNA binding

Biological Process: tRNA aminoacylation for protein translation; hair follicle development; protein folding; tRNA processing; unfolded protein response; regulation of translational fidelity; cerebellar Purkinje cell layer development; gene expression; negative regulation of neuron apoptosis; response to amino acid stimulus; tRNA modification; neuromuscular process controlling balance; alanyl-tRNA aminoacylation

Disease: Epileptic Encephalopathy, Early Infantile, 29; Charcot-marie-tooth Disease, Axonal, Type 2n