7VU7

The Solution structure of the C-terminal domain from flagelliform spidroin

Summary for 7VU7

• Entry DOI: 10.2210/pdb7vu7/pdb
• Descriptor: Flagelliform fibroin (1 entity in total)
• Functional Keywords: flagelliform spidroin, ctd, structural protein
• Biological source: Araneus ventricosus (Orbweaver spider, Epeira ventricosa)
• Total number of polymer chains: 2
• Total formula weight: 22028.43

Authors

Fan, J.S.,Yang, D. (deposition date: 2021-11-01, release date: 2022-04-06, Last modification date: 2024-11-13)

Primary citation

Li, X.,Fan, J.S.,Shi, M.,Lai, C.C.,Li, J.,Meng, Q.,Yang, D.
C-Terminal Domains of Spider Silk Proteins Having Divergent Structures but Conserved Functional Roles.
Biomacromolecules, 23:1643-1651, 2022

PubMed Abstract: Spider silk is self-assembled from silk proteins or spidroins. C-terminal domains (CTDs) of various types of spidroins are relatively conserved in amino acid sequences and are suggested to adopt similar structures and perform similar functional roles in spidroin storage and silk formation. Here, we solved the structure of the CTD from a capture-spiral silk protein (CTD) and characterized its stability and fibril formation in the presence and absence of a reducing agent at different pH values. CTD adopts a dimeric structure with 8 helices, but the CTDs of other types of spidroins exist in a domain-swapped dimeric structure with 10 helices. Despite the structural differences, CTD is pH-responsive in stability and fibril formation, similar to the CTDs from minor and major ampullate spidroins. Thus, the functional role of CTDs in silk fiber formation seems conserved. Comparing wild-type CTD and its mutants, we found that the pH-responsive behavior results from the protonation of H76, which is conserved from different spider species. In addition, the fibril formation rate of CTD correlates with its instability, suggesting that structural changes are involved in fibril formation.

PubMed: 35312302
DOI: 10.1021/acs.biomac.1c01513

Experimental method

SOLUTION NMR