2LPJ

NMR structure of major ampullate spidroin 1 N-terminal domain at pH 7.2

2LPJ の概要

• エントリーDOI: 10.2210/pdb2lpj/pdb
• 関連するPDBエントリー: 2LPI 3lr2
• NMR情報: BMRB: 18262
• 分子名称: Major ampullate spidroin 1 (1 entity in total)
• 機能のキーワード: structural protein
• 由来する生物種: Euprosthenops australis
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 14183.71

構造登録者

Jaudzems, K.,Nordling, K.,Landreh, M.,Rising, A.,Askarieh, G.,Knight, S.D.,Johansson, J. (登録日: 2012-02-14, 公開日: 2012-06-27, 最終更新日: 2024-05-15)

主引用文献

Jaudzems, K.,Askarieh, G.,Landreh, M.,Nordling, K.,Hedhammar, M.,Jornvall, H.,Rising, A.,Knight, S.D.,Johansson, J.
pH-Dependent Dimerization of Spider Silk N-Terminal Domain Requires Relocation of a Wedged Tryptophan Side Chain.
J.Mol.Biol., 422:477-487, 2012

PubMed Abstract: Formation of spider silk from its constituent proteins-spidroins-involves changes from soluble helical/coil conformations to insoluble β-sheet aggregates. This conversion needs to be regulated to avoid precocious aggregation proximally in the silk gland while still allowing rapid silk assembly in the distal parts. Lowering of pH from about 7 to 6 is apparently important for silk formation. The spidroin N-terminal domain (NT) undergoes stable dimerization and structural changes in this pH region, but the underlying mechanisms are incompletely understood. Here, we determine the NMR and crystal structures of Euprosthenops australis NT mutated in the dimer interface (A72R). Also, the NMR structure of wild-type (wt) E. australis NT at pH7.2 and 300 mM sodium chloride was determined. The wt NT and A72R structures are monomers and virtually identical, but they differ from the subunit structure of dimeric wt NT mainly by having a tryptophan (W10) buried between helix 1 and helix 3, while W10 is surface exposed in the dimer. Wedging of the W10 side chain in monomeric NT tilts helix 3 approximately 5-6Å into a position that is incompatible with that of the observed dimer structure. The structural differences between monomeric and dimeric NT domains explain the tryptophan fluorescence patterns of NT at pH7 and pH6 and indicate that the biological function of NT depends on conversion between the two conformations.

PubMed: 22706024
DOI: 10.1016/j.jmb.2012.06.004

実験手法

SOLUTION NMR