Malaria remains a devastating disease affecting millions of people worldwide, and Plasmodium falciparum is the primary agent responsible for severe malaria. The lack of an effective vaccine and the emergence of resistance to current therapies underscore the urgency of understanding the parasite molecular mechanisms to discover novel vulnerabilities. During erythrocyte invasion, respiratory Complex III is essential for parasite survival. The activity of Complex III depends on membrane-bound cytochrome c1 (Cytc1) and soluble cytochrome c (Cytc). In eukaryotes, c-type cytochromes are hemylated by a single enzyme, holocytochrome c synthase (HCCS). In humans, a single HCCS hemylates both Cytc and Cytc1, whereas most eukaryotes, including P. falciparum, encode two HCCS paralogues with different but partially overlapping specificities: one hemylates Cytc (HCCS), and the other hemylates Cytc1 (HCC1S). Previously, we observed that, compared to other organisms studied, the HCCS enzymes in malaria parasites are highly specific to their substrate. We hypothesized that additional factors are involved in this specificity. Our research has focused on identifying these interacting partners through molecular biology and biochemical approaches. Revealing novel cytochrome c1 factors will help us understand how HCC1S is recruited for hemylation and may unveil novel vulnerabilities in the parasite. Additionally, we are interested in understanding how heme is trafficked into the mitochondrion and how it is utilized by the HCCS enzymes. AlphaFold3 structural models suggest the presence of key amino acids that could play a role in heme uptake and its association with the HCCS catalytic core. We aim to evaluate the role of these candidate amino acids through directed mutagenesis to better understand the hemylation mechanisms of these highly conserved enzymes in eukaryotes.