Send to

Choose Destination
See comment in PubMed Commons below
J Struct Biol. 2013 Aug;183(2):205-15. doi: 10.1016/j.jsb.2013.06.004. Epub 2013 Jun 21.

Roles of larval sea urchin spicule SM50 domains in organic matrix self-assembly and calcium carbonate mineralization.

Author information

Physical Chemistry, Department of Chemistry, University of Konstanz, Universitätsstraße 10, PO Box 714, D-78457 Konstanz, Germany.


The larval spicule matrix protein SM50 is the most abundant occluded matrix protein present in the mineralized larval sea urchin spicule. Recent evidence implicates SM50 in the stabilization of amorphous calcium carbonate (ACC). Here, we investigate the molecular interactions of SM50 and CaCO3 by investigating the function of three major domains of SM50 as small ubiquitin-like modifier (SUMO) fusion proteins - a C-type lectin domain (CTL), a glycine rich region (GRR) and a proline rich region (PRR). Under various mineralization conditions, we find that SUMO-CTL is monomeric and influences CaCO3 mineralization, SUMO-GRR aggregates into large protein superstructures and SUMO-PRR modifies the early CaCO3 mineralization stages as well as growth. The combination of these mineralization and self-assembly properties of the major domains synergistically enable the full-length SM50 to fulfill functions of constructing the organic spicule matrix as well as performing necessary mineralization activities such as Ca(2+) ion recruitment and organization to allow for proper growth and development of the mineralized larval sea urchin spicule.


Amorphous calcium carbonate; Biomineralization; C-type lectin; CTL; GRR; IDP; Intrinsic disorder; Matrix assembly; PRR; SM50; SM50 structural domains; SUMO; Spicule matrix proteins; gly-rich region; intrinsically disorder protein; pro-rich region; small ubiquitin-like modifier; spicule matrix protein 50

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center