2LTH

NMR structure of major ampullate spidroin 1 N-terminal domain at pH 5.5

Summary for 2LTH

• Entry DOI: 10.2210/pdb2lth/pdb
• NMR Information: BMRB: 18480
• Descriptor: Major ampullate spidroin 1 (1 entity in total)
• Functional Keywords: structural protein
• Biological source: Euprosthenops australis
• Total number of polymer chains: 2
• Total formula weight: 28367.43

Authors

Otikovs, M.,Jaudzems, K.,Nordling, K.,Landreh, M.,Rising, A.,Askarieh, G.,Knight, S.,Johansson, J. (deposition date: 2012-05-25, release date: 2013-11-27, Last modification date: 2024-05-15)

Primary citation

Kronqvist, N.,Otikovs, M.,Chmyrov, V.,Chen, G.,Andersson, M.,Nordling, K.,Landreh, M.,Sarr, M.,Jornvall, H.,Wennmalm, S.,Widengren, J.,Meng, Q.,Rising, A.,Otzen, D.,Knight, S.D.,Jaudzems, K.,Johansson, J.
Sequential pH-driven dimerization and stabilization of the N-terminal domain enables rapid spider silk formation.
Nat Commun, 5:3254-3254, 2014

PubMed Abstract: The mechanisms controlling the conversion of spider silk proteins into insoluble fibres, which happens in a fraction of a second and in a defined region of the silk glands, are still unresolved. The N-terminal domain changes conformation and forms a homodimer when pH is lowered from 7 to 6; however, the molecular details still remain to be determined. Here we investigate site-directed mutants of the N-terminal domain from Euprosthenops australis major ampullate spidroin 1 and find that the charged residues D40, R60 and K65 mediate intersubunit electrostatic interactions. Protonation of E79 and E119 is required for structural conversions of the subunits into a dimer conformation, and subsequent protonation of E84 around pH 5.7 leads to the formation of a fully stable dimer. These residues are highly conserved, indicating that the now proposed three-step mechanism prevents premature aggregation of spidroins and enables fast formation of spider silk fibres in general.

PubMed: 24510122
DOI: 10.1038/ncomms4254

Experimental method

SOLUTION NMR