Involved in cholesterol side chain degradation (PubMed:22045806, PubMed:29109182). When associated with the ChsH1/ChsH2 hydratase, catalyzes the retroaldol cleavage of 17-hydroxy-3-oxo-4-pregnene-20-carboxyl-CoA (17-HOPC-CoA) produced by the hydratase, forming androst-4-ene-3,17-dione and propionyl-CoA (PubMed:29109182, PubMed:31568719). 17-hydroxy-3-oxochol-4-en-22-oyl-CoA = androst-4-ene-3,17-dione + propanoyl-CoA kcat is 159 sec(-1). Steroid metabolism; cholesterol degradation. Homodimer (PubMed:29109182). Interacts with the ChsH1/ChsH2 hydratase via the DUF35 C-terminal region of ChsH2 (ChsH2-DUF35) (PubMed:29109182, PubMed:31568719). The ChsH1-ChsH2-Ltp2 protein complex is composed of two protomers that form a heterohexameric structure through the Ltp2 dimerization interface (PubMed:31568719). Belongs to the thiolase-like superfamily.