7LQ2

Apo Rr RsiG- crystal form 1

7LQ2 の概要

• エントリーDOI: 10.2210/pdb7lq2/pdb
• 分子名称: RR RsiG, MAGNESIUM ION, ISOPROPYL ALCOHOL, ... (4 entities in total)
• 機能のキーワード: rsig, single-motif, whig, evolution, homodimer, rubrobacter radiotolerans, transcription
• 由来する生物種: Rubrobacter radiotolerans
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 58244.23

構造登録者

Schumacher, M.A.,Brennan, R.G. (登録日: 2021-02-12, 公開日: 2021-07-14, 最終更新日: 2024-11-20)

主引用文献

Schumacher, M.A.,Gallagher, K.A.,Holmes, N.A.,Chandra, G.,Henderson, M.,Kysela, D.T.,Brennan, R.G.,Buttner, M.J.
Evolution of a sigma-(c-di-GMP)-anti-sigma switch.
Proc.Natl.Acad.Sci.USA, 118:-, 2021

PubMed Abstract: Filamentous actinobacteria of the genus have a complex lifecycle involving the differentiation of reproductive aerial hyphae into spores. We recently showed c-di-GMP controls this transition by arming a unique anti-σ, RsiG, to bind the sporulation-specific σ, WhiG. The RsiG-(c-di-GMP)-WhiG structure revealed that a monomeric RsiG binds c-di-GMP via two E(X)S(X)R(X)Q(X)D repeat motifs, one on each helix of an antiparallel coiled-coil. Here we show that RsiG homologs are found scattered throughout the Actinobacteria. Strikingly, RsiGs from unicellular bacteria descending from the most basal branch of the Actinobacteria are small proteins containing only one c-di-GMP binding motif, yet still bind their WhiG partners. Our structure of a (RsiG)-(c-di-GMP)-WhiG complex revealed that these single-motif RsiGs are able to form an antiparallel coiled-coil through homodimerization, thereby allowing them to bind c-di-GMP similar to the monomeric twin-motif RsiGs. Further data show that in the unicellular actinobacterium , the (RsiG)-(c-di-GMP)-WhiG regulatory switch controls type IV pilus expression. Phylogenetic analysis indicates the single-motif RsiGs likely represent the ancestral state and an internal gene-duplication event gave rise to the twin-motif RsiGs inherited elsewhere in the Actinobacteria. Thus, these studies show how the anti-σ RsiG has evolved through an intragenic duplication event from a small protein carrying a single c-di-GMP binding motif, which functions as a homodimer, to a larger protein carrying two c-di-GMP binding motifs, which functions as a monomer. Consistent with this, our structures reveal potential selective advantages of the monomeric twin-motif anti-σ factors.

PubMed: 34290147
DOI: 10.1073/pnas.2105447118

実験手法

X-RAY DIFFRACTION (1.85 Å)