2C04

GMPPCP complex of SRP GTPase Ffh NG Domain at ultra-high resolution

2C04 の概要

• エントリーDOI: 10.2210/pdb2c04/pdb
• 関連するPDBエントリー: 1FFH 1JPJ 1JPN 1LS1 1NG1 1O87 1OKK 1RJ9 1RY1 2BQS 2BQT 2C03 2FFH 2NG1 3NG1
• 分子名称: SIGNAL RECOGNITION PARTICLE PROTEIN, PHOSPHOMETHYLPHOSPHONIC ACID GUANYLATE ESTER, CALCIUM ION, ... (4 entities in total)
• 機能のキーワード: gmppnp, gtp-binding, rna-binding, signaling protein, srp, srp54, nucleotide-binding, signal protein
• 由来する生物種: THERMUS AQUATICUS
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 66265.85

構造登録者

Ramirez, U.D.,Preininger, A.M.,Freymann, D.M. (登録日: 2005-08-25, 公開日: 2007-02-13, 最終更新日: 2023-12-13)

主引用文献

Ramirez, U.D.,Focia, P.J.,Freymann, D.M.
Nucleotide-Binding Flexibility in Ultrahigh-Resolution Structures of the Srp Gtpase Ffh
Acta Crystallogr.,Sect.D, 64:1043-, 2008

PubMed Abstract: Two structures of the nucleotide-bound NG domain of Ffh, the GTPase subunit of the bacterial signal recognition particle (SRP), have been determined at ultrahigh resolution in similar crystal forms. One is GDP-bound and one is GMPPCP-bound. The asymmetric unit of each structure contains two protein monomers, each of which exhibits differences in nucleotide-binding conformation and occupancy. The GDP-bound Ffh NG exhibits two binding conformations in one monomer but not the other and the GMPPCP-bound protein exhibits full occupancy of the nucleotide in one monomer but only partial occupancy in the other. Thus, under the same solution conditions, each crystal reveals multiple binding states that suggest that even when nucleotide is bound its position in the Ffh NG active site is dynamic. Some differences in the positioning of the bound nucleotide may arise from differences in the crystal-packing environment and specific factors that have been identified include the relative positions of the N and G domains, small conformational changes in the P-loop, the positions of waters buried within the active site and shifts in the closing loop that packs against the guanine base. However, ;loose' binding may have biological significance in promoting facile nucleotide exchange and providing a mechanism for priming the SRP GTPase prior to its activation in its complex with the SRP receptor.

PubMed: 18931411
DOI: 10.1107/S090744490802444X

実験手法

X-RAY DIFFRACTION (1.15 Å)