Cloning and expression of eukaryotic initiation factor 4B cDNA: sequence determination identifies a common RNA recognition motif.
Eukaryotic protein synthesis initiation factor 4B (eIF-4B) is an 80,000 dalton polypeptide which is essential for the binding of mRNA to ribosomes. A highly purified preparation of eIF-4B from HeLa cells was subjected to enzymatic cleavage and amino-terminal amino acid sequence analysis. Degenerate oligonucleotide probes were used to isolate a 3851 bp cDNA encoding eIF-4B from a human cDNA library. The DNA encodes a protein comprising 611 residues with a mass of 69,843 daltons. The amino-terminal domain of eIF-4B contains a consensus RNA binding domain present in a number of other RNA binding proteins. Expression of eIF-4B in transfected COS-1 cells yielded a polypeptide which reacted with anti-eIF-4B antiserum and comigrated with purified eIF-4B. Expression of eIF-4B in COS-1 cells resulted in a general inhibition of translation, possibly due to a 50-fold eIF-4B overproduction.
Milburn
S C
SC
Genetics Institute, Cambridge, MA 02140.
Hershey
J W
JW
Davies
M V
MV
Kelleher
K
K
Kaufman
R J
RJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D003001:Cloning, Molecular; D039642:Eukaryotic Initiation Factors; D015870:Gene Expression; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010446:Peptide Fragments / Q000302:isolation & purification; D010448:Peptide Initiation Factors / Q000235:genetics*; D011487:Protein Conformation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection
D039642:Eukaryotic Initiation Factors; D015345:Oligonucleotide Probes; D010446:Peptide Fragments; D010448:Peptide Initiation Factors; D012333:RNA, Messenger; C031799:eIF-4B