A major RuBisCO chaperone. Acts after GroEL-GroES chaperonin to fold and/or assemble the large subunit of RuBisCO (ccbL, rbcL). Cooperates with RbcX in RbcL folding, plays the major role in assembly of dimers into RbcL(8)-Raf1(8) intermediate complexes. RbcS replaces Raf1, leading to holoenzyme formation. In vitro acts as an antagonist to CcmM35, suggesting it might regulate RuBisCO condensation and decondensation. Homodimer. Forms an RbcL(8)-Raf1(8) complex. Each Raf1 dimer clamps the exterior of an RbcL dimer, protecting it. The extreme C-terminus (residues 354-361) inserts into the catalytic pocket of RbcL where the Glu-361 forms a salt bridge with 'Lys-202'. This insertion probably contributes to the assembly of RbcL(8). Forms complexes of many stoichiometries with RbcL with and without RbcS. RbcX and Raf1 can bind simultaneously to RbcL. Has 3 domains, the N-terminal alpha-helical domain, an extended flexible linker and the C-terminal beta-sheet domain. The 2 C-terminal beta-sheet domains are swapped and pack against each other to form the dimer interface. Belongs to the RAF family.