Djimon Hounsou and Alexis Knapp have boarded the post-apocalyptic adventure “One” with shooting starting later this year in South Africa.

Australian filmmaker Murali Thalluri (“2.37”) is directing from his own script. “One” is the first film to be produced under 2011’s South African-Australian co-production treaty.

Main Street Films is co-producing and co-financing the film with Thalluri for MK Create and Kent Smith for the Australia-based Kojo Group. Greig Buckle of Enigma Pictures is co-producing and Main Street chairman Craig Chang and president Harrison Kordestani are executive producing.

Kathy Morgan Intl. is handling international sales.

“One” is set in a world after a virus has wiped out 99% of humanity, leaving those who have survived divided into racial groups all fighting for a cure. Knapp will portray a woman who’s captured and sold to a medical research facility, where it becomes evident that she is immune to the virus.

“Lone Survivor” actor Sammy Shaikh has also joined the cast.

Hounsou’s credits include “In America,” “Blood Diamond” and the upcoming “Fast and Furious 7.” Knapp starred in “Pitch Perfect” and will be seen next in “The Anomaly.”

Main Street’s credits include “Barely Lethal” and “Your Right Mind.”