A single domain of yeast poly(A)-binding protein is necessary and sufficient for RNA binding and cell viability.
The poly(A)-binding protein (PAB) gene of Saccharomyces cerevisiae is essential for cell growth. A 66-amino acid polypeptide containing half of a repeated N-terminal domain can replace the entire protein in vivo. Neither an octapeptide sequence conserved among eucaryotic RNA-binding proteins nor the C-terminal domain of PAB is required for function in vivo. A single N-terminal domain is nearly identical to the entire protein in the number of high-affinity sites for poly(A) binding in vitro (one site with an association constant of approximately 2 X 10(7) M-1) and in the size of the binding site (12 A residues). Multiple N-terminal domains afford a mechanism of PAB transfer between poly(A) strands.
Sachs
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AB
Department of Cell Biology, Stanford University School of Medicine, California 94305.
Davis
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RW
Kornberg
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RD
D001665:Binding Sites; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D002470:Cell Survival; D004252:DNA Mutational Analysis; D009994:Osmolar Concentration; D011061:Poly A / Q000378:metabolism*; D039102:Poly(A)-Binding Proteins; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D013329:Structure-Activity Relationship
D002352:Carrier Proteins; D039102:Poly(A)-Binding Proteins; D011061:Poly A