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Fusion surface structure, function, and dynamics of gamete fusogen HAP2
- Source :
- eLife, Vol 7 (2018)
- Publication Year :
- 2018
- Publisher :
- eLife Sciences Publications Ltd, 2018.
-
Abstract
- HAP2 is a class II gamete fusogen in many eukaryotic kingdoms. A crystal structure of Chlamydomonas HAP2 shows a trimeric fusion state. Domains D1, D2.1 and D2.2 line the 3-fold axis; D3 and a stem pack against the outer surface. Surprisingly, hydrogen-deuterium exchange shows that surfaces of D1, D2.2 and D3 closest to the 3-fold axis are more dynamic than exposed surfaces. Three fusion helices in the fusion loops of each monomer expose hydrophobic residues at the trimer apex that are splayed from the 3-fold axis, leaving a solvent-filled cavity between the fusion loops in each monomer. At the base of the two fusion loops, Arg185 docks in a carbonyl cage. Comparisons to other structures, dynamics, and the greater effect on Chlamydomonas gamete fusion of mutation of axis-proximal than axis-distal fusion helices suggest that the apical portion of each monomer could tilt toward the 3-fold axis with merger of the fusion helices into a common fusion surface.
- Subjects :
- HAP2
fusion loop
dynamics
Medicine
Science
Biology (General)
QH301-705.5
Subjects
Details
- Language :
- English
- ISSN :
- 2050084X
- Volume :
- 7
- Database :
- Directory of Open Access Journals
- Journal :
- eLife
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.fe98dd9d798e455fb016355889f9e3d7
- Document Type :
- article
- Full Text :
- https://doi.org/10.7554/eLife.39772