5K8G

Crystal structure of a putative peptide-binding domain of MpAFP

Summary for 5K8G

• Entry DOI: 10.2210/pdb5k8g/pdb
• Descriptor: Antifreeze protein, CALCIUM ION (3 entities in total)
• Functional Keywords: cell adhesion, peptide binding, antifreeze protein
• Biological source: Marinomonas primoryensis
• Total number of polymer chains: 1
• Total formula weight: 57250.52

Authors

Guo, S.,Campbell, R.,Davies, P. (deposition date: 2016-05-30, release date: 2017-09-06, Last modification date: 2024-04-03)

Primary citation

Guo, S.,Stevens, C.A.,Vance, T.D.R.,Olijve, L.L.C.,Graham, L.A.,Campbell, R.L.,Yazdi, S.R.,Escobedo, C.,Bar-Dolev, M.,Yashunsky, V.,Braslavsky, I.,Langelaan, D.N.,Smith, S.P.,Allingham, J.S.,Voets, I.K.,Davies, P.L.
Structure of a 1.5-MDa adhesin that binds its Antarctic bacterium to diatoms and ice.
Sci Adv, 3:e1701440-e1701440, 2017

PubMed Abstract: Bacterial adhesins are modular cell-surface proteins that mediate adherence to other cells, surfaces, and ligands. The Antarctic bacterium uses a 1.5-MDa adhesin comprising over 130 domains to position it on ice at the top of the water column for better access to oxygen and nutrients. We have reconstructed this 0.6-μm-long adhesin using a "dissect and build" structural biology approach and have established complementary roles for its five distinct regions. Domains in region I (RI) tether the adhesin to the type I secretion machinery in the periplasm of the bacterium and pass it through the outer membrane. RII comprises ~120 identical immunoglobulin-like β-sandwich domains that rigidify on binding Ca to project the adhesion regions RIII and RIV into the medium. RIII contains ligand-binding domains that join diatoms and bacteria together in a mixed-species community on the underside of sea ice where incident light is maximal. RIV is the ice-binding domain, and the terminal RV domain contains several "repeats-in-toxin" motifs and a noncleavable signal sequence that target proteins for export via the type I secretion system. Similar structural architecture is present in the adhesins of many pathogenic bacteria and provides a guide to finding and blocking binding domains to weaken infectivity.

PubMed: 28808685
DOI: 10.1126/sciadv.1701440

Experimental method

X-RAY DIFFRACTION (2 Å)