geranylgeranyltransferase-2 (GGTase-2, rab GGTase)

Function

• transfers C-20 isoprenyl moiety via pyrophosphate
• prefers Leu as X of CaaX motif
• recognizes carboxy terminal motifs of form Cys-X-Cys or Cys-Cys, typical of rab proteins
• unlike farnesyltransferase, GGT-2 is inhibited by Zn+2, & recognizes other domains of its target rab proteins in addition to the C-terminus, resulting in multiple prenyl groups attached to rab proteins

Structure

• heterodimer of an alpha & a beta subunit

More general terms

• prenyltransferase

Additional terms

• cholesterol biosynthesis