Pentameric organization of the ribosomal stalk accelerates recruitment of ricin a chain to the ribosome for depurination.

ABSTRACT: Ribosome inactivating proteins (RIPs) depurinate a universally conserved adenine in the α-sarcin/ricin loop (SRL) and inhibit protein synthesis at the translation elongation step. We previously showed that ribosomal stalk is required for depurination of the SRL by ricin toxin A chain (RTA). The interaction between RTA and ribosomes was characterized by a two-step binding model, where the stalk structure could be considered as an important interacting element. Here, using purified yeast ribosomal stalk complexes assembled in vivo, we show a direct interaction between RTA and the isolated stalk complex. Detailed kinetic analysis of these interactions in real time using surface plasmon resonance (SPR) indicated that there is only one type of interaction between RTA and the ribosomal stalk, wh

SUBMITTER: Li XP 

PROVIDER: S-EPMC3009872 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature