Purification and properties of alanyl-tRNA synthetase from Bombyx mori: a monomeric enzyme.
Alanyl-tRNA synthetase was purified from the posterior silk glands of Bombyx mori by ammonium sulfate fractionation and chromatography on DEAE-Sephacel and hydroxyapatite columns. The yield was about 100 mg of the enzyme per 1 kg of the glands. The enzyme required both L-alanine and alanine tRNA for pyrophosphate formation from ATP. The PPi formation was observed even after tRNA was fully aminoacylated. The enzyme was found to be a monomer of 115K daltons by SDS-polyacrylamide gel electrophoresis, gel filtration and suberimidate cross-linking experiments. The monomeric enzyme did not dimerize in the presence of the alanine tRNA. The enzyme and the tRNA formed a 1:1 complex. The results indicate that Bombyx mori alanyl-tRNA synthetase functions in a monomeric state.
D000412:Alanine-tRNA Ligase / Q000302:isolation & purification* / Q000378:metabolism; D000596:Amino Acids / Q000032:analysis; D000604:Amino Acyl-tRNA Synthetases / Q000302:isolation & purification*; D000818:Animals; D012831:Bombyx / Q000201:enzymology*; D002848:Chromatography, DEAE-Cellulose; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism
D000596:Amino Acids; D012346:RNA, Transfer, Amino Acyl; D000604:Amino Acyl-tRNA Synthetases; D000412:Alanine-tRNA Ligase