TY - JOUR
T1 - Mutually exclusive binding of messenger RNA and initiator methionyl transfer RNA to eukaryotic initiation factor 2
AU - Rosen, Haim
AU - Kaempfer, Raymond
N1 - Funding Information:
Supported by grants from the Israel GSF (Muenchen).
PY - 1979/11/28
Y1 - 1979/11/28
N2 - Eukaryotic initiation factor 2 (eIF-2), purified to at least 98% homogeneity as judged by polyacrylamide gel electrophoresis in sodium dodecyl sulfate, and containing no detectable amounts of eukaryotic initiation factor 4B (eIF-4B), is active both in the binding of Met-tRNA and in the binding of globin mRNA. The mRNA-binding activity is completely sensitive to competitive inhibition by Met-tRNA, provided GTP is present, but not by uncharged tRNA. By contrast, binding of mRNA to partially purified eIF-4B is not inhibited by Met-tRNAf. These results establish that the only mRNA-binding component in the eIF-2 preparation is eIF-2 itself, and show that a given molecule of eIF-2 can either bind to a molecule of mRNA, or form a ternary complex with Met-tRNAf and GTP, but cannot do both at once.
AB - Eukaryotic initiation factor 2 (eIF-2), purified to at least 98% homogeneity as judged by polyacrylamide gel electrophoresis in sodium dodecyl sulfate, and containing no detectable amounts of eukaryotic initiation factor 4B (eIF-4B), is active both in the binding of Met-tRNA and in the binding of globin mRNA. The mRNA-binding activity is completely sensitive to competitive inhibition by Met-tRNA, provided GTP is present, but not by uncharged tRNA. By contrast, binding of mRNA to partially purified eIF-4B is not inhibited by Met-tRNAf. These results establish that the only mRNA-binding component in the eIF-2 preparation is eIF-2 itself, and show that a given molecule of eIF-2 can either bind to a molecule of mRNA, or form a ternary complex with Met-tRNAf and GTP, but cannot do both at once.
UR - http://www.scopus.com/inward/record.url?scp=0018803620&partnerID=8YFLogxK
U2 - 10.1016/0006-291X(79)91542-0
DO - 10.1016/0006-291X(79)91542-0
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C2 - 518643
AN - SCOPUS:0018803620
SN - 0006-291X
VL - 91
SP - 449
EP - 455
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -