Equilibration of methionine into the Met-tRNA pool of rabbit reticulocyte lysates. Additional evidence that deacylation of ribosomal subunit-bound Met-tRNAf does occur in heme-deficiency.

We have measured the rate of equilibration of [35S]methionine into the Met-tRNA pool of rabbit reticulocyte lysate as in [FEBS Lett. (1982) 143, 301-305]. Our results indicate that hemin-deficiency inhibits the equilibration of methionine into the tRNA pool much less than protein synthesis or the equilibration of alanine into the tRNA pool, whereas cycloheximide inhibits these processes similarly. This finding is consistent with our previous data and supports the hypothesis that with hemin-deficiency much of the Met-tRNAf that becomes bound to 40 S subunits subsequently undergoes enzymatic deacylation.