Open AccessThe Subunit Structure of Phenylalanyl‐tRNA Synthetase of Escherichia coli
Author(s) -
Kosakowski M. H. J. E.,
Böck A.
Publication year - 1970
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1970.tb00821.x
Subject(s) - protein subunit , escherichia coli , enzyme , transfer rna , urea , biochemistry , gel electrophoresis , biology , polyacrylamide gel electrophoresis , chemistry , microbiology and biotechnology , rna , gene
Fingerprints of tryptic digests of phenylalanyl‐tRNA synthetase of Escherichia coli NP 3 suggest that the smallest identical subunit is one fourth of the size of the native protein (mol. wt. 181000). Determination of the subunit size by gel electrophoresis reveals a molecular weight of 43000 ± 2000. By the criteria employed the enzyme therefore seems to be composed of four identical subunits. Phenylalanyl‐tRNA synthetase which has been denatured by treatment with 8 M urea is able to reform active enzyme indistinguishable by its size from the native protein. Again, a size of about 45000 was determined for the subunits active in the association reaction.