A single domain of yeast poly(A)-binding protein is necessary and sufficient for RNA binding and cell viability

Mol Cell Biol. 1987 Sep;7(9):3268-76. doi: 10.1128/mcb.7.9.3268-3276.1987.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Binding Sites
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Division
  • Cell Survival
  • DNA Mutational Analysis
  • Osmolar Concentration
  • Poly A / metabolism*
  • Poly(A)-Binding Proteins
  • Saccharomyces cerevisiae / physiology*
  • Structure-Activity Relationship


  • Carrier Proteins
  • Poly(A)-Binding Proteins
  • Poly A