Identification and characterization of cap-binding proteins from yeast.
Photochemical cross-linking of Saccharomyces cerevisiae ribosomal salt wash preparations to cap-labeled mRNA reveals, in addition to the previously characterized 24-kDa cap-binding protein (eIF-4E), the presence of two novel cap-binding proteins (CBPs) of apparent molecular masses of 96 and 150 kDa. Cross-linking of the 96-kDa CBP was found to occur spontaneously without UV light induction. Based on the ATP/Mg2+ requirements, the three CBPs can be subdivided into two classes: 1) ATP/Mg2+ independent (24- and 150 kDa) and 2) Mg2+ dependent (96 kDa). The co-purification of the 24- and 150-kDa CBPs through several different chromatographic steps is consistent with the existence of a yeast CBP complex, possibly analogous to mammalian eIF-4F.
Goyer
C
C
Department of Biochemistry, McGill University, Montreal, Canada.
Altmann
M
M
Trachsel
H
H
Sonenberg
N
N
D000227:Adenine Nucleotides / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D002352:Carrier Proteins / Q000302:isolation & purification* / Q000378:metabolism; D002846:Chromatography, Affinity; D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D008274:Magnesium / Q000378:metabolism; D008970:Molecular Weight; D010448:Peptide Initiation Factors / Q000302:isolation & purification* / Q000378:metabolism; D010777:Photochemistry; D011233:Precipitin Tests; D039381:RNA Cap-Binding Proteins; D012315:RNA Caps / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000032:analysis*
D000227:Adenine Nucleotides; D002352:Carrier Proteins; D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D010448:Peptide Initiation Factors; D039381:RNA Cap-Binding Proteins; D012315:RNA Caps; D000255:Adenosine Triphosphate; D008274:Magnesium