1NPR

CRYSTAL STRUCTURE OF AQUIFEX AEOLICUS NUSG IN C222(1)

1NPR の概要

• エントリーDOI: 10.2210/pdb1npr/pdb
• 関連するPDBエントリー: 1M1G 1M1H 1NPP
• 分子名称: Transcription antitermination protein nusG (2 entities in total)
• 機能のキーワード: transcription factor, nusg, transcription
• 由来する生物種: Aquifex aeolicus
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28041.70

構造登録者

Knowlton, J.R.,Bubunenko, M.,Andrykovitch, M.,Guo, W.,Routzhan, K.M.,Waugh, D.S.,Court, D.L.,Ji, X. (登録日: 2003-01-18, 公開日: 2003-03-11, 最終更新日: 2024-10-30)

主引用文献

Knowlton, J.R.,Bubunenko, M.,Andrykovitch, M.,Guo, W.,Routzhan, K.M.,Waugh, D.S.,Court, D.L.,Ji, X.
A Spring-Loaded State of NusG in Its Functional Cycle Is Suggested by X-ray Crystallography and Supported by Site-Directed Mutants
Biochemistry, 42:2275-2281, 2003

PubMed Abstract: Transcription factor NusG is present in all prokaryotes, and orthologous proteins have also been identified in yeast and humans. NusG contains a 27-residue KOW motif, found in ribosomal protein L24 where it interacts with rRNA. NusG in Escherichia coli (EcNusG) is an essential protein and functions as a regulator of Rho-dependent transcription termination, phage lambda N and rRNA transcription antitermination, and phage HK022 Nun termination. Relative to EcNusG, Aquifex aeolicus NusG (AaNusG) and several other bacterial NusG proteins contain a variable insertion sequence of approximately 70 residues in the central region of the molecule. Recently, crystal structures of AaNusG in space groups P2(1) and I222 have been reported; the authors conclude that there are no conserved dimers among the contacting molecules in the crystals [Steiner, T., Kaiser, J. T., Marinkovic, S., Huber, R., and Wahl, M. C. (2002) EMBO J. 21, 4641-4653]. We have independently determined the structures of AaNusG also in two crystal forms, P2(1) and C222(1), and surprisingly found that AaNusG molecules form domain-swapped dimers in both crystals. Additionally, polymerization is also observed in the P2(1) crystal. A unique "ball-and-socket" junction dominates the intermolecular interactions within both oligomers. We believe that this interaction is a clue to the function of the molecule and propose a spring-loaded state in the functional cycle of NusG. The importance of the ball-and-socket junction for the function of NusG is supported by the functional analysis of site-directed mutants.

PubMed: 12600194
DOI: 10.1021/bi0272508

実験手法

X-RAY DIFFRACTION (2.21 Å)