Paper Citing NAMD - Abstract
Camargo, Hendricka; Nusspaumer, Gretel; Abia, David; Briceno, Veronica; Remacha, Miguel; Ballesta, Juan P. G.
The amino terminal end determines the stability and assembling capacity of eukaryotic ribosomal stalk proteins P1 and P2
NUCLEIC ACIDS RESEARCH, 39:3735-3743, MAY 2011
The eukaryotic ribosomal proteins P1 and P2 bind to protein P0 through their N-terminal domain to form the essential ribosomal stalk. A mutational analysis points to amino acids at positions 2 and 3 as determinants for the drastic difference of Saccharomyces cerevisiae P1 and P2 half-life, and suggest different degradation mechanisms for each protein type. Moreover, the capacity to form P1/P2 heterodimers is drastically affected by mutations in the P2 beta four initial amino acids, while these mutations have no effect on P1 beta. Binding of P2 beta and, to a lesser extent, P1 beta to the ribosome is also seriously affected showing the high relevance of the amino acids in the first turn of the NTD alpha-helix 1 for the stalk assembly. The negative effect of some mutations on ribosome binding can be reversed by the presence of the second P1/P2 couple in the ribosome, indicating a stabilizing structural influence between the two heterodimers. Unexpectedly, some mutations totally abolish heterodimer formation but allow significant ribosome binding and, therefore, a previous P1 and P2 association seems not to be an absolute requirement for stalk assembly. Homology modeling of the protein complexes suggests that the mutated residues can affect the overall protein conformation.
