Updated project metadata. The merozoite surface protein-1 (MSP-1) is the most abundant protein on the surface of the erythrocyte-invading Plasmodium merozoite, the causative agent of malaria. MSP-1 is essential for merozoite formation, entry into and escape from erythrocytes, and is a promising vaccine candidate. We solved monomeric and dimeric structures of full-length MSP-1 construct MSP-1D as previously used in a successful phase 1a clinical trial (Blank et al. 2020). CS-MS was used to validate the de novo built atomic model.