Methylation of elongation factor EF-Tu affects the rate of trypsin degradation and tRNA-dependent GTP hydrolysis

Abstract

The role of methylation of elongation factor EF-Tu from Escherichia coli was investigated. The methylated factor was obtained from cells harvested at the late stationary growth phase. Submethylated forms of the factor were obtained from either bacteria grown to the mid-logarithmic phase or cells cultured in the presence of ethionine. When fully methylated EF-Tu was treated in the presence of trypsin, it showed a greatly reduced rate of degradation compared with both types of undermethylated EF-Tu factors. The methylation of EF-Tu appeared not to affect the rate of GDP and GTP exchange. However, aminoacyl-tRNA-stimulated GTPase activity determined in the presence of kirromycin was greatly increased when the EF-Tu was methylated.