Comparative study of subunits of phenylalanyl‐tRNA synthetase from Escherichia coli and Thermus thermophilus

FEBS Letters

Lavrik, Olga I.¹  Mashanov-Golikov, Anton V.²  Ankilova, Valentina N.¹  Wolfson, Aleksey²  Bobkova, Ekaterina V.¹ 

[1] Novosibirsk Institute of Bioorganic Chemistry, Siberian Division of USSR Academy of Sciences, Lavrentiev prospect 8, 630090 Novosibirsk, USSR;Bakh Institute of Biochemistry, USSR Academy of Sciences, Leninsky prospect 33, 117071 Moscow, USSR

关键词: Thermophilic phenylalanyl-tRNA synthetase;    Oligomeric structure;    Isoelectric point;    PheRS;    phenylalanyl-tRNA synthetase;    Th;    th;    Thermus thermophilus;   

DOI  :  10.1016/0014-5793(91)81234-Y

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

FPLC separation of α- and β-subunits of phenylalanyl-tRNA synthetases from E. coli MRE-600 and Thermus thermophilus HB8 has been carried out in the presence of urea. Native α-subunits of both enzymes were primarily α₂-dimers and tended to aggregate. Most E. coli enzyme β-subunits were monomeric and only a small fraction was represented by β₂-dimers. All thermophilic β-subunits were β-dimers. It was shown that monomers and all forms of homologous subunits had no catalytic activity in tRNA^Phe aminoacylation. For the enzymes and their subunits, titration curves were obtained and isoelectric points were determined. The comparison of the relative surface charges indicated similarity of the surfaces of entire enzymes and the corresponding β-subunits. α-Subunits displayed a distinctly different pH dependence of the surface charge. A spatial model of the oligomeric structure and a putative mechanism for its formation are discussed.

【 授权许可】

Unknown