Catalyzes the condensation of L-serine with palmitoyl-CoA (hexadecanoyl-CoA) to produce 3-oxosphinganine. H(+) + hexadecanoyl-CoA + L-serine = 3-oxosphinganine + CO2 + CoA kcat is 0.15 sec(-1). Optimum pH is 7.0 to 8.0. Lipid metabolism; sphingolipid metabolism. Homodimer. Belongs to the class-II pyridoxal-phosphate-dependent aminotransferase family.