Serine palmitoyltransferase small subunit B (Sptssb)

Stimulates the activity of serine palmitoyltransferase (SPT). The composition of the serine palmitoyltransferase (SPT) complex determines the substrate preference, complexes with this subunit showing a clear preference for more acyl-CoAs.

The SPTLC1-SPTLC2-SPTSSB complex indicates a strong preference for C18-CoA substrate, while the SPTLC1-SPTLC3-SPTSSB isozyme shows an ability to utilize a broader range of acyl-CoAs, without apparent preference (By similarity). .