3AGV

Crystal structure of a human IgG-aptamer complex

3AGV の概要

• エントリーDOI: 10.2210/pdb3agv/pdb
• 分子名称: Ig gamma-1 chain C region, 5'-R(*GP*GP*AP*GP*GP*(UFT)P*GP*(CFZ)P*(UFT)P*(CFZ)P*(CFZ)P*GP*AP*AP*A*GP*GP*AP*AP*(CFZ)P*(UFT)P*(CFZ)P*(CFZ)P*A)-3', alpha-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-alpha-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-6)-alpha-D-mannopyranose, ... (6 entities in total)
• 機能のキーワード: igg, rna aptamer, immune system-rna complex, immune system/rna
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Secreted: P01857
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 65623.40

構造登録者

Nomura, Y.,Sugiyama, S.,Sakamoto, T.,Miyakawa, S.,Adachi, H.,Takano, K.,Murakami, S.,Inoue, T.,Mori, Y.,Nakamura, Y.,Matsumura, H. (登録日: 2010-04-08, 公開日: 2010-11-10, 最終更新日: 2024-11-20)

主引用文献

Nomura, Y.,Sugiyama, S.,Sakamoto, T.,Miyakawa, S.,Adachi, H.,Takano, K.,Murakami, S.,Inoue, T.,Mori, Y.,Nakamura, Y.,Matsumura, H.
Conformational plasticity of RNA for target recognition as revealed by the 2.15 A crystal structure of a human IgG-aptamer complex
Nucleic Acids Res., 38:7822-7829, 2010

PubMed Abstract: Aptamers are short single-stranded nucleic acids with high affinity to target molecules and are applicable to therapeutics and diagnostics. Regardless of an increasing number of reported aptamers, the structural basis of the interaction of RNA aptamer with proteins is poorly understood. Here, we determined the 2.15 Å crystal structure of the Fc fragment of human IgG1 (hFc1) complexed with an anti-Fc RNA aptamer. The aptamer adopts a characteristic structure fit to hFc1 that is stabilized by a calcium ion, and the binding activity of the aptamer can be controlled many times by calcium chelation and addition. Importantly, the aptamer-hFc1 interaction involves mainly van der Waals contacts and hydrogen bonds rather than electrostatic forces, in contrast to other known aptamer-protein complexes. Moreover, the aptamer-hFc1 interaction involves human IgG-specific amino acids, rendering the aptamer specific to human IgGs, and not crossreactive to other species IgGs. Hence, the aptamer is a potent alternative for protein A affinity purification of Fc-fusion proteins and therapeutic antibodies. These results demonstrate, from a structural viewpoint, that conformational plasticity and selectivity of an RNA aptamer is achieved by multiple interactions other than electrostatic forces, which is applicable to many protein targets of low or no affinity to nucleic acids.

PubMed: 20675355
DOI: 10.1093/nar/gkq615

実験手法

X-RAY DIFFRACTION (2.15 Å)