Alanyl-tRNA synthetase (AARS)

Alanyl-tRNA synthetase (AARS) belongs to the family of ligases, specifically those forming carbon-oxygen bonds in aminoacyl-tRNA and related compounds. This enzyme participates in alanine and aspartate metabolism and aminoacyl-tRNA biosynthesis. Alanyl-tRNA synthetase (AlaRS) catalyzes synthesis of Ala-tRNA (Ala) and hydrolysis of mis-acylated Ser- and Gly-tRNA (Ala) at 2 different catalytic sites. Their role is not confined to catalyze the attachment of amino acids to transfer RNAs and thereby establish the rules of genetic code by virtue of matching the nucleotide triplet of anticodon with cognate amino acid. Under apoptotic conditions in cell culture, the full-length enzyme is secreted, and the two cytokine activities can be generated by leukocyte elastase, an extracellular protease. Secretion of this tRNA synthetase may contribute to apoptosis both by arresting translation and producing needed cytokines. This protein could be an attractive target of drugs against bacterial, fungal and parasitic infections.

Alanyl-tRNA synthetase (AARS) Related Areas

 

Alanyl-tRNA synthetase (AARS) Alternative Names

CMT2N, alaRS,alanine tRNA ligase 1,cytoplasmic [Homo sapiens]

AI316495,C76919,MGC37368,sti, alaRS,alanine-tRNA ligase, alanyl-tRNA synthetase [Mus musculus]

Summaries for Alanyl-tRNA synthetase (AARS)

Entrez Gene summary for AARS:

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]

OMIM - description for Alanyl-tRNA synthetase:

Description The AARS gene encodes alanyl-tRNA synthetase. Each of the amino acid synthetases catalyzes the attachment of their respective amino acids to the appropriate tRNA. The class II Escherichia coli and human alanyl-tRNA synthetases cross-acylate their respective tRNAs and require, for aminoacylation, an acceptor helix G3:U70 basepair that is conserved in evolution (Shiba et al., 1995). Some of the amino acid synthetases are targets for autoantibodies in the autoimmune disease polymyositis/dermatomyositis (Nichols et al., 1995) including histidyl-RS (142810), threonyl-RS (187790), isoleucyl-RS (600709), glycyl-RS (600287) and alanyl-RS.

Wikipedia summary for Alanyl-tRNA synthetase:

An aminoacyl tRNA synthetase (aaRS) is an enzyme that catalyzes the esterification of a specific amino acid or its precursor to one of all its compatible cognate tRNAs to form an aminoacyl-tRNA. This is sometimes called "charging" the tRNA with the amino acid. Once the tRNA is charged, a ribosome can transfer the amino acid from the tRNA onto a growing peptide, according to the genetic code.

Human Alanyl-tRNA synthetase (AARS) Protein General Information

 

• Protein names: Alanyl-tRNA synthetase, Short name=AlaRS
• Sequence length: 968 AA.
• Domain: Consists of three domains; the N-terminal catalytic domain, the editing domain and the C-terminal C-Ala domain. The editing domain removes incorrectly charged amino acids, while the C-Ala domain, along with tRNA(Ala), serves as a bridge to cooperatively bring together the editing and aminoacylation centers thus stimulating deacylation of misacylated tRNAs
  The C-terminal C-Ala domain (residues 756 to 968), along with tRNA(Ala), serves as a bridge to cooperatively bring together the editing and aminoacylation centers thus stimulating deacylation of misacylated tRNAs. The human domain can be used in vitro to replace the corresponding domain in E.coli.
• Sequence similarities: Aalanyl-tRNA synthetase belongs to the class-II aminoacyl-tRNA synthetase family.
• Post-translational modification: ISGylated.
• Subunit structure: Monomer.
• Subcellular location: Cytoplasm
• Catalytic activity: ATP + L-alanine + tRNA(Ala) = AMP + diphosphate + L-alanyl-tRNA(Ala).
• Cofactor: Aalanyl-tRNA synthetase binds 1 zinc ion per subunit
• Involvement in disease: Defects in alanyl-tRNA synthetase are the cause of Charcot-Marie-Tooth disease type 2N (CMT2N) [MIM:613287]. 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.

General information above from UniProt

Function for Alanyl-tRNA synthetase (AARS) Protein

UniProtKB:

Alanyl-tRNA synthetase 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). AARS also edits incorrectly charged tRNA(Ala) via its editing domain.

Genatlas:

• Alanyl-tRNA synthetase is enzymes that interpret the RNA code and attach specific aminoacids to the tRNAs that contain the cognate trinucleotide anticodons
• Alanyl-tRNA synthetase is target autoantibodies in immune polymyositis/dermatomyositis
• Alanyl-tRNA synthetase ligates amino acids to their cognate tRNAs (Sang Lee 2002)

Phenotype Information for Alanyl-tRNA synthetase (AARS)

• Gene/Locus: AARS, CMT2N
• Phenotype: Charcot-Marie-Tooth disease, axonal, type 2N

Phenotype Information for Alanyl-tRNA synthetase from OMIM (Online Mendelian Inheritance in Man)