Top cofit genes for Rru_A1998 from Rhodospirillum rubrum S1H
ribulose-bisphosphate carboxylase-like protein; rubisco-like protein (NCBI)
SEED: similar to ribulose-1,5-bisphosphate carboxylase, Type III, too
KEGG: ribulose-bisphosphate carboxylase large chain
Or look for negative cofitness