Open AccessCommon chaperone activity in the G-domain of trGTPase protects L11–L12 interaction on the ribosome
Author(s) -
Dandan Zhang,
Liu Guangqiao,
Jiaying Xue,
Jizhong Lou,
Knud H. Nierhaus,
Weimin Gong,
Yan Qin
Publication year - 2012
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/gks833
Subject(s) - ctd , biology , chaperone (clinical) , ribosomal protein , ribosome , mutagenesis , docking (animal) , computational biology , biochemistry , microbiology and biotechnology , rna , mutation , medicine , oceanography , nursing , pathology , gene , geology
Translational GTPases (trGTPases) regulate all phases of protein synthesis. An early event in the interaction of a trGTPase with the ribosome is the contact of the G-domain with the C-terminal domain (CTD) of ribosomal protein L12 (L12-CTD) and subsequently interacts with the N-terminal domain of L11 (L11-NTD). However, the structural and functional relationships between L12-CTD and L11-NTD remain unclear. Here, we performed mutagenesis, biochemical and structural studies to identify the interactions between L11-NTD and L12-CTD. Mutagenesis of conserved residues in the interaction site revealed their role in the docking of trGTPases. During docking, loop62 of L11-NTD protrudes into a cleft in L12-CTD, leading to an open conformation of this domain and exposure of hydrophobic core. This unfavorable situation for L12-CTD stability is resolved by a chaperone-like activity of the contacting G-domain. Our results suggest that all trGTPases-regardless of their different specific functions-use a common mechanism for stabilizing the L11-NTD•L12-CTD interactions.