Monomeric prefusion structure of an extremophile gamete fusogen and stepwise formation of the postfusion trimeric state

Abstract

Studies in the postfusion structures of the conserved gamete fusogen HAP2 show a trimeric state typical of viral class II fusion proteins. Here, the authors present the crystal structure of a prefusion state of Cyanidioschyzon merolae HAP2 and low resolution structures of intermediates in the pathway to its trimeric postfusion state.