Heterologous expression of hornwort Rubisco from Anthoceros agrestis in Escherichia coliwith expression of Rubisco large and small subunits, chaperonins 60alpha/beta and chaperonin 20 as well as a suite of assembly factors, Raf1/Raf2/RbcX2/BSD2/RbcX1. Rubisco kinetics show differences in Rubisco assembled with and without RbcX1/2.