Messenger RNA binding protein purified from reticulocyte polyribosomes

Publisher Website
Google Scholar
Abstract
One of the proteins in the 0.5 M KCl eluate of rabbit reticulocyte polyribosomes which bind poly(A)-rich mRNA was purified to apparent homogeneity using ammonium sulfate fractionation and phosphocellulose, hydroxylapatite and DEAE-cellulose column chromatography. The protein appears to contain 2 subunits of apparent MW 66,700 and 56,400 with a 1:1 stoichiometry, since an apparent MW of 110,000 was determined using Sephadex G-200 chromatography and an s020,w [sedimentation coefficient at 20.degree. C in H2O] of 5.6 was obtained with rate-zonal sedimentation. The mRNA binding activity banded at pH 5.2-5.5 on isoelectric-focusing polyacrylamide gel electrophoresis. Protein-dependent binding appeared to be specific, since other natural or synthetic RNA, including tRNA, ribosomal RNA and poly(riboadenylic acid), were 90- to 250-fold less effective than mRNA at competing for binding of [3H]poly(adenylic acid)-rich mRNA. Poly(riboguanylic acid), however, was more efficiently bound by this protein than mRNA.

This publication has 0 references indexed in Scilit: