2K6H

NMR structure of an unusually 28 kDa Active Mutant of Maize Ribosome-Inactivating protein (MOD)

2K6H の概要

• エントリーDOI: 10.2210/pdb2k6h/pdb
• 分子名称: Ribosome-inactivating protein (1 entity in total)
• 機能のキーワード: maize ribosome-inactivating protein, plant defense, protein synthesis inhibitor, solution structure, mod, nmr spectroscopy, hydrolase, toxin, zymogen
• 由来する生物種: Zea mays (maize)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 27901.33

構造登録者

Yang, Y.,Mak, A.N.,Shaw, P.C.,Sze, K.H. (登録日: 2008-07-09, 公開日: 2009-07-14, 最終更新日: 2024-05-29)

主引用文献

Yang, Y.,Mak, A.N.,Shaw, P.C.,Sze, K.H.
Solution structure of an active mutant of maize ribosome-inactivating protein (MOD) and its interaction with the ribosomal stalk protein P2.
J.Mol.Biol., 395:897-907, 2010

PubMed Abstract: Ribosome-inactivating proteins (RIPs) are N-glycosidases that depurinate a specific adenine residue in the conserved sarcin/ricin loop of ribosomal RNA. This modification renders the ribosome unable to bind the elongation factors, thereby inhibiting the protein synthesis. Maize RIP, a type III RIP, is unique compared to the other type I and type II RIPs because it is synthesized as a precursor with a 25-residue internal inactivation region, which is removed in order to activate the protein. In this study, we describe the first solution structure of this type of RIP, a 28-kDa active mutant of maize RIP (MOD). The overall protein structure of MOD is comparable to those of the other type I RIPs and the A-chain of type II RIPs but shows significant differences in specific regions, including (1) shorter beta6 and alphaB segments, probably for accommodating easier substrate binding, and (2) an alpha-helix instead of an antiparallel beta-sheet in the C-terminal domain, which has been reported to be involved in binding ribosomal protein P2 in some RIPs. Furthermore, NMR chemical shift perturbation experiments revealed that the P2 binding site on MOD is located at the N-terminal domain near the internal inactivation region. This relocation of the P2 binding site can be rationalized by concerted changes in the electrostatic surface potential and 3D structures on the MOD protein and provides vital clues about the underlying molecular mechanism of this unique type of RIP.

PubMed: 19900464
DOI: 10.1016/j.jmb.2009.10.051

実験手法

SOLUTION NMR